FIELD OF THE INVENTION
[0001] The invention generally relates to medical devices and procedures pertaining to prosthetic
heart valves. More specifically, the invention relates to replacement of heart valves
that may have malformations and/or dysfunctions. Embodiments of the invention relate
to an anchor or docking device that can hold and maintain a positioning of a prosthetic
heart valve for replacing the function of a native heart valve, for example, for a
mitral or tricuspid valve replacement procedure, as well as deployment procedures
associated with the implantation of such an anchor or docking device and/or of an
assembly including the anchor or docking device and a prosthetic heart valve.
RELATED APPLICATIONS
BACKGROUND
[0003] Referring first to Figs. 1 and 2, the mitral valve 50 controls the flow of blood
between the left atrium 52 and the left ventricle 54 of the human heart. After the
left atrium 52 receives oxygenated blood from the lungs via the pulmonary veins, the
mitral valve 50 permits the flow of the oxygenated blood from the left atrium 52 into
the left ventricle 54. When the left ventricle 54 contracts, the oxygenated blood
that was held in the left ventricle 54 is delivered through the aortic valve 56 and
the aorta 58 to the rest of the body. Meanwhile, the mitral valve should close during
ventricular contraction to prevent any blood from flowing back into the left atrium.
[0004] When the left ventricle contracts, the blood pressure in the left ventricle increases
substantially, which serves to urge the mitral valve closed. Due to the large pressure
differential between the left ventricle and the left atrium during this time, a large
amount of pressure is placed on the mitral valve, leading to a possibility of prolapse,
or eversion of the leaflets of the mitral valve back into the atrium. A series of
chordae tendineae 62 therefore connect the leaflets of the mitral valve to papillary
muscles located on the walls of the left ventricle, where both the chordae tendineae
and the papillary muscles are tensioned during ventricular contraction to hold the
leaflets in the closed position and to prevent them from extending back towards the
left atrium. This helps prevent backflow of oxygenated blood back into the left atrium.
The chordae tendineae 62 are schematically illustrated in both the heart cross-section
of Fig. 1 and the top view of the mitral valve of Fig. 2.
[0005] A general shape of the mitral valve and its leaflets as viewed from the left atrium
is shown in Fig. 2. Commissures 64 are located at the ends of the mitral valve 50
where the anterior leaflet 66 and the posterior leaflet 68 come together. Various
complications of the mitral valve can potentially cause fatal heart failure. One form
of valvular heart disease is mitral valve leak or mitral regurgitation, characterized
by abnormal leaking of blood from the left ventricle through the mitral valve back
into the left atrium. This can be caused, for example, by dilation of the left ventricle
causing the native mitral leaflets to not coapt completely, resulting in a leak, by
damage to the native leaflets, or weakening of (or damage to) the chordae tendineae
and/or papillary muscles. In these circumstances, it may be desirable to repair the
mitral valve or to replace the functionality of the mitral valve with that of a prosthetic
heart valve.
[0006] With respect to valve replacement, while open surgical procedure options are more
readily available, there has been much less development in terms of commercially available
ways to replace a mitral valve through catheter implantation and/or other minimal
or less invasive procedures. Replacement of a mitral valve is more difficult than
aortic valve replacement in many respects, for example, due to the non-circular physical
structure of the mitral valve, its sub-annular anatomy, and more difficult access
to the valve.
[0007] It could be beneficial to use prosthetic aortic valves or similar circular or cylindrical
valve prostheses for mitral valve replacements. However, one of the most prominent
obstacles for mitral valve replacement is effective anchoring or retention of the
valve at the mitral position, due to the valve being subject to a large cyclic load.
As noted above, another issue with mitral valve replacement is the size and shape
of the native mitral annulus, as can be seen in Fig. 2. Aortic valves are more circular
or cylindrical in shape than mitral valves. Also, the mitral and tricuspid valves
are both larger than the aortic valve, and more elongate in shape, making them more
difficult and unconventional sites for implanting a replacement valve with a generally
circular or cylindrical valve frame. A circular prosthetic valve that is too small
can result in leaking around the implant (i.e., paravalvular leakage) if a good seal
is not established around the valve, while a circular prosthetic valve that is too
large can stretch out and damage the narrower parts of the native mitral annulus.
Further, in many cases, the need for aortic valve replacement arises due, for example,
to aortic valve stenosis, where the aortic valve narrows due to calcification or other
hardening of the native leaflets. Therefore, the aortic annulus generally forms a
more compact, rigid, and stable anchoring site for a prosthetic valve than the mitral
annulus, which is both larger than the aortic annulus and non-circular. Instances
of mitral valve regurgitation are unlikely to provide such a good anchoring site.
Also, the presence of the chordae tendineae and other anatomy at the mitral position
can form obstructions that make it much more challenging to adequately anchor a device
at the mitral position.
[0008] Other obstacles to effective mitral valve replacement can stem from the large cyclic
loads the mitral valve undergoes and the need to establish a sufficiently strong and
stable anchoring and retention. Also, even a slight shift in the alignment of the
valve can still lead to blood flow through the valve or other parts of the heart being
obstructed or otherwise negatively impacted.
SUMMARY
[0009] One way to apply existing circular or cylindrical transcatheter valve technology
to non-circular valve replacement (e.g., mitral valve replacement, tricuspid valve
replacement, etc.) would be to use an anchor (e.g., a mitral anchor) or docking station
that forms or otherwise provides a more circular docking site at the native valve
position (e.g., mitral valve position) to hold such prosthetic valves. In this manner,
existing expandable transcatheter valves developed for the aortic position, or similar
valves that have been slightly modified to more effectively replicate mitral valve
function, could be more securely implanted in such docking stations positioned at
the native valve annulus (e.g., native mitral annulus). The docking station can first
be positioned at the native valve annulus, and thereafter, the valve implant or transcatheter
heart valve can be advanced and positioned through the docking station while in a
collapsed position, and can then be expanded, for example, via self-expansion (e.g.,
in the case of valves that are constructed with NiTi or another shape memory material),
balloon expansion, or mechanical expansion, so that the frame of the prosthetic valve
pushes radially against the docking station and/or tissue between the two to hold
the valve in place. Preferably, the docking station can also be delivered minimally
or less invasively, for example, via the same or similar transcatheter approaches
as used for delivery of a transcatheter heart valve, so that a completely separate
procedure is not needed to implant the docking station prior to delivery of the prosthetic
valve.
[0010] It would therefore be desirable to provide devices and methods that can be utilized
to facilitate the docking or anchoring of such valves. Embodiments of the invention
provide a stable docking station or docking device for retaining a prosthetic valve
(e.g., a prosthetic mitral valve). Other features are provided to improve the deployment,
positioning, stability, and/or integration of such docking stations and/or replacement
prostheses intended to be held therein. These devices and methods will more securely
hold prosthetic valves, and can also prevent or greatly reduce regurgitation or leaking
of blood around the prosthetic valves. Such docking devices and methods can be used
for various valve replacement procedures, for example, for mitral, tricuspid, pulmonary,
or aortic valve replacements, to provide more secure and robust anchoring and holding
of valve implants at the native annuluses at those positions.
[0011] Docking devices for docking a prosthetic valve at a native valve (e.g., mitral valve,
tricuspid valve, etc.) of a heart can include various features, components, and characteristics.
For example, such docking devices can include a coiled anchor that has at least one
central turn (e.g., a full rotation or partial-rotation central turn) defining a central
turn diameter. The at least one central turn can be one or more functional turns/coils.
The coiled anchor can also include a lower turn extending from the at least one central
turn defining a diameter that is greater than the central turn diameter. The lower
turn can be a leading turn/coil. The coiled anchor can also include an upper turn
connected to the central turn. The upper turn can be one or more stabilizing turns/coils.
The upper turn can be shaped to have a first diameter along a first axis and a second
diameter along a second axis. The first axis diameter of the upper turn can be greater
than the central turn diameter, and the second axis diameter can be greater than the
central turn diameter and less than the lower turn diameter. The various coiled anchors
described herein can be configured to be implanted at the native valve (e.g., native
mitral valve, tricuspid valve, etc.) with at least a portion of the at least one central
turn of the coiled anchor positioned in a chamber (e.g., a left ventricle) of the
heart and around valve leaflets of the native valve.
[0012] Any of the coiled anchors described herein can also include an extension having a
length extending from an upper end of the at least one central turn to an upper turn/coil
or stabilization turn/coil. The extension can have a smaller or reduced thickness
compared to other parts of the coiled anchor, e.g., the at least one central turn,
upper turn, lower turn, etc. The extension can extend vertically at an angle between
60-120 degrees, 70-110 degrees, 80-100 degrees, 90 degrees relative to the at least
one central turn.
[0013] The various docking devices for docking a prosthetic valve at a native valve of a
heart can have a coiled anchor (e.g., which can be the same as or similar to other
coiled anchors described in this disclosure) that has a proximal tip and a distal
tip. The coiled anchor can include at least one central turn (e.g., a full or partial
central turn, which can be the same as or similar to other central or functional turns
described in this disclosure). The at least one central turn can have a first thickness
and define a central turn diameter. Any of the coiled anchors described herein can
also include an extension having a length extending from an upper end of the at least
one central turn. The coiled anchor can also include an upper turn (e.g., with can
be the same as or similar to other upper turns or stabilizing turns/coils described
in this disclosure) extending from an upper end of the extension. The extension can
have a second thickness that is less than the first thickness. The upper turn can
have a third thickness that is greater than the second thickness. As discussed above,
the coiled anchor can configured to be implanted at the native valve (e.g., native
mitral valve, tricuspid valve, etc.) with at least a portion of the at least one full
or partial central turn of the coiled anchor positioned in a chamber (e.g., left ventricle)
of the heart and around valve leaflets (e.g., mitral valve leaflets) of the native
heart valve.
[0014] The various docking devices for docking a prosthetic valve at a native valve of a
heart can also have a coiled anchor (e.g., which can be the same as or similar to
other coiled anchors described in this disclosure) that has a proximal tip and a distal
tip and at least one central turn (e.g., a full or partial central turn, which can
be the same as or similar to other central turns/coils or functional turns/coils described
in this disclosure) that defines a diameter. The coiled anchor can also have an upper
turn that is connected to the at least one central turn. A cover layer can surround
the coiled anchor along all or at least a part of the at least one central turn. The
cover layer can be connected to the coiled anchor. At least one friction enhancing
layer can be disposed over the coiled anchor and/or the cover layer. The at least
one friction enhancing layer can be disposed over at least a portion of the at least
one central turn. The coiled anchor can be configured such that no portion of the
upper turn is covered by the friction enhancing layer. The coiled anchor can also
be configured to be implantable at a native valve (e.g., a native mitral valve, etc.)
with at least a portion of the at least one central turn of the coiled anchor positioned
in a chamber (e.g., left ventricle) of the heart and around valve leaflets of the
native valve.
[0015] Any of the coiled anchors of any of the docking devices described herein can include
one or more cover layers that surround all or at least part of the coiled anchor or
a core of the coiled anchor. For example, a cover layer can surround all or at least
part of the at least one central turn (or all of the central turn(s)/coil(s) or functional
turn(s)/coil(s) of the coiled anchor) and/or other parts of the coiled anchor. The
cover layer can be connected to the coiled anchor in various ways. The cover layer
can be a high friction cover layer, a low friction cover layer, or both a low friction
cover layer and a high friction cover layer used together. The low friction cover
layer can be configured to surround a core of the coiled anchor (e.g., the full length
of the coiled anchor) and extend past the proximal tip and/or distal tip. The low
friction cover layer can form a tapered or rounded tip at its distal end and/or at
its proximal end. A high friction cover layer or higher friction cover layer (e.g.,
higher than the low friction cover layer) can surround a portion of the low friction
cover layer and/or a portion of the coiled anchor (e.g., all or a part of the at least
one central turn).
[0016] Any of the coiled anchors described herein can include at least one friction enhancing
element or multiple friction enhancing elements. The at least one friction enhancing
element or friction enhancing elements can be positioned over all or a portion of
the coiled anchor or a covering/layer on the coiled anchor. The at least one friction
enhancing element can be or include a plurality of bulges on the surface of the coiled
anchor or on the surface of the covering. The bulges can be made of PET, polymer,
fabric, or another material. The bulges can extend along a length of the coiled anchor
or the covering along at least a part of the central turn(s)/coil(s).
Optionally, the at least one friction enhancing element can be or include a plurality
of lock and key cutouts in an outer surface of the coiled anchor. The lock cutouts
can be grooves formed in the outer surface of the coiled anchor, and the key cutouts
can be protrusions extending outward from the coiled anchor, which can be sized and
shaped to fit into the lock cutouts.
[0017] Systems for implanting a docking device at a native valve of a heart can include
a docking device (e.g., any docking device described above or elsewhere in this disclosure).
The docking device can include an opening or bore, and the system can include a suture
threaded through the opening or bore. The system can also include a delivery catheter,
and a pusher device disposed in the delivery catheter. The pusher device can include
a central lumen that accepts the suture or through which the suture passes. The pusher
device and suture can be arranged such that pulling the suture pulls the coiled anchor
against the pusher device, and retracting the pusher device into the delivery catheter
retracts the coiled anchor into the delivery catheter. The suture can be disposed
in the central lumen such that pulling the suture and/or the pusher device proximally
relative to the delivery catheter retracts the coiled anchor or delivery device into
the delivery catheter.
[0018] A docking device for docking a prosthetic valve at a native valve of a heart can
have a coiled anchor that includes a hollow tube. The hollow tube can have a proximal
lock feature and a distal lock feature. There can be a plurality of cuts through a
portion of the tube. The cuts can have a pattern and shape that incorporates one or
both of longitudinal and transverse cuts. Where the cuts have a pattern and shape
that incorporate both longitudinal and transverse cuts, these can form teeth and grooves
in the hollow tube. The docking device can also have a wire, and the distal end of
the wire can be secured to the distal lock feature. A length of the wire (e.g., the
full length or a portion thereof) can extend through the hollow tube and apply a radially
inward tension on the hollow tube. The hollow tube is configured to at least partially
encircle leaflets of a native mitral valve and provide a docking surface for an expandable
prosthetic valve.
[0019] Methods used to implant a docking device for a prosthetic valve at a native heart
valve can include a variety of steps (e.g., any of the steps described throughout
this disclosure). The docking device implanted with these methods can be any of the
docking devices described herein. For example, a docking device implantable with these
steps can have a coiled anchor having at least one full or partial turn defining a
central diameter, an extension having a length extending from an upper end of the
at least one central turn, and an upper turn extending from an upper end of the extension.
As distal end of a delivery catheter can be positioned into a first chamber (e.g.,
a left atrium) of a heart. Optionally, the delivery catheter can be advanced and positioned
through a guide sheath previously implanted. The delivery catheter can contain the
docking device in a first configuration. A distal end of a docking device can be advanced
from the delivery catheter so that the docking device adopts a second configuration
as it is advanced and/or when it is implanted. The docking device is advanced through
a valve annulus (e.g., a native mitral valve annulus) and into a second chamber of
the heart (e.g., the left ventricle) such that a distal tip loosely encircles any
chordae and native leaflets of the native valve (e.g., of a mitral valve). The extension
of the docking device can be advanced such that its upper end is positioned in the
first chamber (e.g., the left atrium). The upper portion of the docking device can
be advanced into the first chamber (e.g., the left atrium) and released, such that
the upper portion is in contact with the first chamber wall (e.g., the left atrium
wall). A replacement prosthetic valve can be implanted in the docking device. For
example, a replacement valve can be inserted in an inner space defined by the docking
device in the second configuration. The replacement valve can be radially expanded
until there is a retention force between the replacement valve and the docking device
to hold the replacement valve in a stable position. Native leaflets or other tissue
can be clamped between the delivery device and the prosthetic valve.
[0020] Valve replacement can be realized through the use of a coiled anchor or docking device
at the native valve site for docking an expandable transcatheter heart valve therein.
The coiled anchors or docking devices provide a more stable base or site against which
the prosthetic valves can be expanded. Embodiments of the invention thus provide a
more robust way to implant a replacement heart valve, even at sites such as a native
mitral annulus, where the annulus itself may be non-circular or otherwise variably
shaped.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Further features and advantages of the invention will become apparent from the description
of embodiments using the accompanying drawings. In the drawings:
Fig. 1 shows a schematic cross-sectional view of a human heart;
Fig. 2 shows a schematic top view of a mitral valve annulus of a heart;
Fig. 3 shows a perspective view of a coil anchor according to a first embodiment of
the invention;
Fig. 4 shows a side view of the coil anchor of Fig. 3;
Fig. 5 shows a top view of the coil anchor of Figs. 3 and 4;
Fig. 6 shows a cross-sectional view of a portion of a heart during a step of delivering
the coil anchor of Figs. 3 to 5 to the native mitral annulus;
Fig. 7 shows a cross-sectional view of a portion of a heart during a further step
of delivering the coil anchor of Figs. 3 to 5 to the native mitral annulus;
Fig. 8 shows a cross-sectional view of a portion of a heart with the coil anchor of
Figs. 3 to 5 positioned at the native mitral annulus;
Fig. 9 shows a cross-sectional view of a portion of a heart with the coil anchor of
Figs. 3 to 5 and a prosthetic mitral valve implanted at the native mitral annulus;
Fig. 10 shows a perspective view of a modified version of the coil anchor of Figs.
3 to 5;
Fig. 11 schematically shows an open view of a laser-cut tube to be used as a coil
anchor according to an embodiment of the invention;
Fig. 11A schematically shows an open view of a laser-cut tube to be used as a coil
anchor and a tensioning wire according to an embodiment of the invention;
Fig. 12 shows a top view of the laser-cut coil anchor of Fig. 11 in an assembled state;
Fig. 13 shows a perspective view of the laser-cut coil anchor of Fig. 11 in an assembled
and actuated state, and with the frame of a prosthetic valve held therein;
Fig. 14 shows a top view of a modified coil anchor with end hooks;
Fig. 15 shows a schematic view of another modified coil anchor with a high friction
cover layer;
Fig. 16 shows a schematic view of yet another modified coil anchor with friction elements;
Fig. 16A shows a cross-section view of the embodiment shown in Fig. 16;
Fig. 17 shows a schematic view of a coil anchor incorporating both a high friction
covering and friction elements;
Fig. 18 shows still another modified coil anchor with surface features to facilitate
interlocking or position retention between adjacent coils;
Fig. 19 shows an exemplary coil anchor that is a variation of the coil anchor ofFig.
10;
Fig. 19A shows a cross-section view of an embodiment of the coil anchor;
Fig. 20 schematically shows a top view of an embodiment of a coil anchor implanted
and arranged at a desired position at the native mitral annulus;
Fig. 21 shows the coil anchor of Fig. 19 further including marker bands;
Fig. 22 shows a cross-section of a proximal end of the coil anchor of Fig. 19;
Fig. 22A shows an embodiment of a suture looped through a coiled anchor;
Fig. 22B shows another embodiment of a suture looped through a coiled anchor;
Fig. 22C shows an embodiment of a suture looped through a coiled anchor;
Fig. 23 shows a distal end of a coil skeleton or core of a docking device according
to an embodiment of the invention;
Fig. 24 shows a distal end of a coil skeleton or core of a docking device according
to another embodiment of the invention;
Fig. 25 shows a proximal end of a coil skeleton or core of a docking device according
to an embodiment of the invention; and
Fig. 26 shows a proximal end of the docking device of Fig. 25, with a cover layer
attached over the coil skeleton or core.
DETAILED DESCRIPTION
[0022] Disclosed herein are various coiled anchoring or docking devices, which can be used
in conjunction with expandable transcatheter heart valves (THV) at a native valve
annulus (e.g., mitral or tricuspid valve annulus), in order to more securely implant
and hold the prosthetic valve at the implant site. Anchoring/docking devices according
to embodiments of the invention provide or form a more circular and/or stable annulus
at the implant site, in which prosthetic valves having circular or cylindrically-shaped
valve frames or stents can be expanded or otherwise implanted. In addition to providing
an anchoring site for the prosthetic valve, the anchoring/docking devices can be sized
and shaped to cinch or draw the native valve (e.g., mitral, tricuspid, etc.) anatomy
radially inwards. In this manner, one of the main causes of valve regurgitation (e.g.,
functional mitral regurgitation), specifically enlargement of the heart (e.g., left
ventricle) and/or valve annulus, and consequent stretching out of the native valve
(e.g., mitral) annulus, can be at least partially offset or counteracted. Some embodiments
of the anchoring or docking devices further include features which, for example, are
shaped and/or modified to better hold a position or shape of the docking device during
and/or after expansion of a prosthetic valve therein. By providing such anchoring
or docking devices, replacement valves can be more securely implanted and held at
various valve annuluses, including at the mitral annulus which does not have a naturally
circular cross-section.
[0023] A coil-shaped anchor/docking device according to an exemplary embodiment of the invention
is shown in Figs. 3 to 5. Fig. 3 shows a perspective view of the anchor or docking
device 1, Fig. 4 shows a side view of the anchor/docking device 1, and Fig. 5 shows
a top view of the anchor/docking device 1.
[0024] The docking device 1 includes a coil with a plurality of turns extending along a
central axis of the docking device 1. The coil can be continuous and can extend generally
helically, with various differently sized and shaped sections, as described in greater
detail below. The docking device 1 shown in Figs. 3 to 5 is configured to best fit
at the mitral position, but can be shaped similarly or differently in other embodiments
for better accommodation at other native valve positions as well.
[0025] The docking device 1 includes a central region 10 with approximately three full coil
turns having substantially equal inner diameters. The central region 10 of the docking
device 1 serves as the main landing region or holding region for holding the expandable
prosthetic valve or THV when the docking device 1 and the valve prosthesis are implanted
into a patient's body. Other embodiments of the docking device 1 can have a central
region 10 with more or less than three coil turns, depending for example, on the patient's
anatomy, the amount of vertical contact desired between the docking device 1 and the
valve prosthesis (e.g., THV), and/or other factors. The coils of the central region
10 can also be referred to as the "functional coils," since the properties of these
coils contribute the most to the amount of retention force generated between the valve
prosthesis, the docking device 1, and the native mitral leaflets and/or other anatomical
structures.
[0026] Various factors can contribute to the total retention force between the docking device
1 and the prosthetic valve held therein. A main factor is the number of turns included
in the functional coils, while other factors include, for example, an inner diameter
of the functional coils, a friction force between the coils and the prosthetic valve,
and the strength of the prosthetic valve and the radial force the valve applies on
the coil. A docking device can have a variety of numbers of coil turns. The number
of functional turns can be in ranges from just over a half turn to 5 turns, or one
full turn to 5 turns, or more. In one embodiment with three full turns, an additional
one half turn is included in the ventricular portion of the docking device. In another
embodiment, there can be three full turns total in the docking device. In one embodiment,
in the atrial portion of the docking device, there can be one-half to three-fourths
turn or one-half to three-fourths of a circle. While a range of turns is provided,
as the number of turns in a docking device is decreased, the dimensions and/or materials
of the coil and/or the wire that the coil is made from can also change to maintain
a proper retention force. For example, the diameter of the wire can be larger and/or
the diameter of the function coil turn(s) in a docking device with fewer coils. There
can be a plurality of coils in the atrium and in the ventricle.
[0027] A size of the functional coils or coils of the central region 10 is generally selected
based on the size of the desired THV to be implanted into the patient. Generally,
the inner diameter of the functional coils/turns (e.g., of the coils/turns of the
central region 10 of the docking device 1) will be smaller than the outer diameter
of the expandable heart valve, so that when the prosthetic valve is expanded in the
docking device, additional radial tension or retention force will act between the
docking device and the prosthetic valve to hold the prosthetic valve in place. The
retention force needed for adequate implantation of a prosthetic valve varies based
on the size of the prosthetic valve and on the ability of the assembly to handle mitral
pressures of approximately 180 mm Hg. For example, based on benchtop studies using
a prosthetic valve with a 29 mm expanded outer diameter, a retention force of at least
18.5 N is needed between the docking device and the prosthetic valve in order to securely
hold the prosthetic valve in the docking device and to resist or prevent mitral regurgitation
or leakage. However, under this example, to meet this 18.5 N retention force requirement
with statistical reliability, a target average retention force should be substantially
greater, for example, approximately 30 N.
[0028] In many embodiments, the retention force between the docking device and the valve
prosthesis reduces dramatically when a difference between the outer diameter of the
prosthetic valve in its expanded state and the inner diameter of the functional coils
is less than about 5 mm, since the reduced size differential would be too small to
create sufficient retention force between the components. For example, when, as in
one embodiment, a prosthetic valve with a 29 mm expanded outer diameter is expanded
in a set of coils with a 24 mm inner diameter, the retention force observed is about
30 N, but when the same prosthetic valve is expanded in a set of coils with a 25 mm
inner diameter (e.g., only 1 mm larger), the retention force observed drops significantly
to only 20 N. Therefore, for valves and docking devices of this type, in order to
create a sufficient retention force between the docking device and a 29 mm prosthetic
valve, the inner diameter of the functional coils (e.g., the coils of the central
region 10 of docking device 1) should be 24 mm or less. Generally, the inner diameter
of the functional coils (e.g., central region 10 of the docking device 1) should be
selected to be at least about 5 mm less than the prosthetic valve that is selected
for implantation, though other features and/or characteristics (e.g., friction enhancing
features, material characteristics, etc.) can be used to provide better retention
if other sizes or size ranges are used, as various factors can affect retention force.
In addition, a size of the inner diameter of the functional coils or central region
10 can also be selected to draw the mitral anatomy closer together, in order to at
least partially offset or counteract mitral regurgitation that is caused by stretching
out of the native valve annulus as a result of, for example, left ventricular enlargement.
[0029] It is noted that the desired retention forces discussed above are applicable to embodiments
for mitral valve replacements. Therefore, other embodiments of the docking device
that are used for replacement of other valves can have different size relationships
based on the desired retention forces for valve replacement at those respective positions.
In addition, the size differentials can also vary, for example, based on the materials
used for the valve and/or the docking device, whether there are any other features
to prevent expansion of the functional coils or to enhance friction/locking, and/or
based on various other factors.
[0030] In embodiments where the docking device 1 is used at the mitral position, the docking
device can first be advanced and delivered to the native mitral valve annulus, and
then set at a desired position, prior to implantation of the THV. Preferably, the
docking device 1 is flexible and/or made of a shape memory material, so that the coils
of the docking device 1 can be straightened for delivery via a transcatheter approach
as well. In another embodiment, the coil can be made of another biocompatible material,
such as stainless steel. Some of the same catheters and other delivery tools can be
used for both delivery of the docking device 1 and the prosthetic valve, without having
to perform separate preparatory steps, simplifying the implantation procedure for
the end user.
[0031] The docking device 1 can be delivered to the mitral position transatrially from the
left atrium, transseptally through the atrial septum, or can be delivered to the mitral
position via one of various other known access points or procedures. Figs. 6 and 7
illustrate some steps during delivery of a docking device 1 to the mitral position
using a transseptal approach, where a guide sheath 1000 is advanced through vasculature
to the right atrium and through the atrial septum of the heart to the left atrium,
and a delivery catheter 1010 is advanced through the guide sheath 1000 passing through
the vasculature, right atrium, and septum into the left atrium. As can best be seen
in Fig. 6, the docking device 1 can be advanced through a distal end of the delivery
catheter 1010 positioned in the left atrium (e.g., positioned at a commissure), through
the native mitral annulus, for example, at a commissure of the native mitral valve,
and into the left ventricle. The distal end of the docking device 1 then circles around
the mitral anatomy (e.g., native mitral leaflets and/or the chordae tendineae) located
in the left ventricle, so that all or at least some of the native leaflets and/or
the chordae tendineae are corralled or gathered by and held in (e.g., encircled by)
the coils of the docking device 1.
[0032] However, since the functional coils/turns or coils/turns of the central region 10
of the docking device 1 are kept relatively small in diameter (e.g., the central region
10 in one embodiment can have an inner diameter of approximately 24 mm (e.g., ± 2
mm) or another diameter smaller than the THV and/or the native annulus) in order to
increase retention force with the prosthetic valve, it might be difficult to advance
the docking device 1 around the existing leaflets and/or chordae to a desired position
relative to the native mitral annulus. This is especially true, if the entire docking
device 1 is made to have the same small diameter as the central region 10. Therefore,
referring back to Figs. 3 to 5, the docking device 1 can have a distal or lower region
20 that makes up a leading coil/turn (or leading ventricular coil/turn) of the docking
device 1, which has a diameter that is greater than the diameter of the functional
coils/turns or of the coils/turns of central region 10.
[0033] Features of the mitral anatomy in the left ventricle have variable dimensions, and
can have an approximately 35 mm to 45 mm greatest width on a long axis. The diameter
or width of the leading coil/turn (e.g., ventricular coil/turn) of the lower region
20 can therefore be selected to be larger to more easily navigate a distal or leading
tip 21 of the docking device 1 around and encircle the features of the mitral anatomy
(e.g., leaflets and/or chordae tendineae). Various sizes and shapes are possible,
for example, in one embodiment, the diameter could be any size from 25 mm to 75 mm.
The term "diameter" as used in this disclosure does not require that a coil/turn be
a complete or perfectly-shaped circle, but is generally used to refer to a greatest
width across opposing points of the coil/turn. For example, with respect to the leading
coil/turn, diameter can be measured from the distal tip 21 to the opposite side, as
if the lower region 20 or leading coil/turn formed a complete rotation, or the diameter
can be considered double a radius of curvature of the leading coil/turn. In one embodiment,
the lower region 20 of the docking device 1 (e.g., the leading coil/turn) has a diameter
(e.g.,) of approximately 43 mm (e.g., ± 2 mm), in other words the radius of curvature
at the leading coil/turn can be approximately 21.5 mm. Having a leading coil/turn
with a larger size than the functional coils can help more easily guide the coils
around and/or through the chordae geometry, and most importantly, adequately around
both native leaflets of the mitral valve. Once the distal tip 21 is navigated around
the desired mitral anatomy, the remaining coils of the docking device 1 can also be
guided around the same features, where the reduced size of the other coils can cause
the corralled anatomical features to be pulled slightly radially inwardly. Meanwhile,
the length of the enlarged lower region 20 is generally kept relatively short, to
prevent or avoid obstruction or interference of the flow of blood along the left ventricular
outflow tract by the lower region 20. For example, in one embodiment, the enlarged
lower region 20 extends for only about half a loop or rotation. With a lower region
20 having this relatively short length, when a prosthetic valve is expanded into the
docking device 1 and the coils of the docking device 1 start to unwind slightly due
to the size differential between the docking device and the prosthetic valve, the
lower region 20 may also be drawn in and shift slightly. Under this example, after
expansion of the prosthetic valve, the lower region 20 can be similar in size and
be aligned substantially with the functional coils of the docking device 1, rather
than continuing to project away from the functional coils, thereby reducing any potential
flow disturbances. Other docking device embodiments can have lower regions that are
longer or shorter, depending on the particular application.
[0034] The docking device 1 in Figs. 3 to 5 also includes an enlarged proximal or upper
region 30 that makes up a stabilizing coil/turn (e.g., which can be an atrial coil/turn)
of the docking device 1. When the docking device 1 has been placed in a desired position
and orientation at the native mitral annulus, the entire docking device 1 is released
from the delivery catheter 1010, and thereafter a prosthetic valve (e.g., a THV) is
delivered to the docking device 1. During a transient or intermediate stage of the
implantation procedure, that is, during the time between the deployment and release
of the docking device 1 and final delivery of the prosthetic valve, there is a possibility
that the coil could be shifted and/or dislodged from its desired position or orientation,
for example, by regular heart function. Shifting of the docking device 1 could potentially
lead to a less secure implantation, misalignment, and/or other positioning issues
for the prosthetic valve. A stabilization feature or coil can be used to help stabilize
the docking device in the desired position. For example, the docking device 1 can
include the upper region 30 with an enlarged stabilization coil/turn (e.g., an enlarged
atrial coil/turn) intended to be positioned in the circulatory system (e.g. in the
left atrium) such that it can stabilize the docking device. For example, the upper
region 30 or stabilization coil/turn can be configured to abut or push against the
walls of the circulatory system (e.g., against the walls of the left atrium), in order
to improve the ability of the docking device 1 to stay in its desired position prior
to the implantation of the prosthetic valve.
[0035] The stabilization coil/turn (e.g., atrial coil/turn) at the upper region 30 of the
docking device 1 in the embodiment shown extends for about or nearly one full turn
or rotation, and terminates at a proximal tip 31. In other embodiments, the stabilization
coil/turn (e.g., atrial coil) can extend for more or less than one turn or rotation,
depending for example on the amount of contact desired between the docking device
and the circulatory system (e.g., with the walls of the left atrium) in each particular
application. The radial size of the stabilization coil/turn (e.g., atrial coil) at
the upper region 30 can also be significantly larger than the size of the functional
coils in the central region 10, so that the stabilization coil/turn (e.g., atrial
coil) flares or extends sufficiently outwardly in order to make contact with the walls
of the circulatory system (e.g., the walls of the left atrium). For example, in one
embodiment, a major diameter 32 or width of the upper region 30 is approximately 50
mm (e.g., ± 2 mm), or about twice as large as the coils in the central region 10.
A bottom region of the left atrium generally narrows towards the native mitral annulus.
Therefore, when the docking device 1 is properly deployed at the mitral position,
the stabilization coil/turn (e.g., atrial coil) of the upper region 30 sits and pushes
against the walls of the left atrium, to help keep or hold the docking device 1 at
a relatively high desired position and orientation, and preventing or reducing shifting
of the docking device 1 towards the left ventricle, until the THV is advanced to and
expanded in the docking device 1. Once the prosthetic valve (e.g., THV) is expanded
within the docking the device, the force generated between the functional coils and
prosthetic valve (e.g., with tissue, leaflets, etc. therebetween) is sufficient to
secure and stabilize the docking device and prosthetic valve without needing the stabilization
coil/turn.
[0036] Optionally, the stabilization coil/turn (e.g., atrial coil) of the upper region 30
can be non-circular in shape, and in the embodiment shown, is biased and arranged
in an elliptical or ovoid shape. As illustrated in Fig. 5, an elliptical or other
non-circular shape stabilization coil/turn (e.g., atrial coil) can have a major axis
diameter 32, D
1 (i.e., a greatest width of the coil turn) and a minor axis diameter 33, D
2 (i.e., a smallest end-to-end width). The widths/diameters can be chosen based on
the size of the anatomy of a portion of a circulatory system (e.g., based on the size
of human's left atrium). The major axis diameter (or greatest width), D
1, can range from 40 to 100 mm, or can be from 40-80, mm, or from 40-75 mm. The minor
axis diameter (or smallest width) D
2 can range from 20 to 80 mm, or from 20 to 75 mm. While a major diameter/width D
1 of the stabilization coil/turn (e.g., atrial coil) can be approximately 50 mm, a
diameter/width D
2 along a minor axis of the stabilization coil/turn (e.g., atrial coil) can be much
smaller, for example, only slightly larger than the diameter of the central region
10 of the docking device 1, as can best be seen in the top view of the docking device
1 in Fig. 5. In other embodiments, the biasing of the upper region of the docking
device can be effected in other ways. For example, the stabilization coil/turn (e.g.,
atrial coil) of the upper region 30 can still be substantially circular, and/or the
stabilization coil/turn can be biased in one direction, such that a center of the
upper region is offset from the center of other portions of the docking device. This
biasing of the shape of the upper region 30 of the docking device 1 can, for example,
increase contact between the docking device 1 and the wall of the left atrium or other
anatomy in the radial direction that the upper region 30 extends farthest from other
portions of the docking device 1. The stabilization coil/turn (e.g., atrial coil)
can be biased such that when viewed from a bird's eye view (Fig. 20), the stabilization
coil/turn (e.g., atrial coil) has a center that is off center from the center of the
functional coils by about 50 to 75% of the diameter of the functional turns. The stabilization
turn (e.g., atrial turn) of the coil can be compliant, and flex inwards. This accommodates
anatomy (e.g., left atrium anatomy) where the stabilization coil/turn (e.g., atrial
coil) may have a major or minor axis diameter that is larger than the atrium or other
anatomy itself.
[0037] Importantly, the docking device 1 can be rotated or otherwise oriented so that the
narrower portion of the upper region 30, or the portion that extends the least radially
outwardly, is directed in an optimal way. For example, when implanted in a native
mitral valve, towards the wall of the left atrium that opposes or pushes against the
left ventricular outflow tract, so that the amount of pressure applied by the docking
device 1 against that portion of the atrial wall is reduced. In this manner, an amount
of displacement of that portion of the wall into the left ventricular outflow tract
will also be reduced, and the enlarged upper region 30 can therefore avoid obstructing,
interfering with, or otherwise affecting the blood flow through the left ventricular
outflow tract.
[0038] With the enlarged upper region 30, the docking device 1 can be more securely held
or retained at a proper positioning and orientation at the native valve annulus (e.g.,
native mitral annulus) before the THV is implanted and expanded therein. Such self-retention
of the docking device 1 will more effectively prevent undesirable shifting or tilting
of the docking device 1 before the prosthetic valve is fully implanted, thereby improving
performance of the implant as a whole.
[0039] Figs. 6 to 9 show some of the steps that can be used for delivering and implanting
a docking device (e.g., docking device 1 or other docking devices described elsewhere
herein) and a THV at the mitral position. While these focus on the mitral position,
similar steps can be used in other valve locations, e.g., at the tricuspid valve position.
The docking device can be the docking device 1 described above with respect to Figs.
3 to 5 or another similar docking device (e.g., other docking devices herein), and
the THV is generally a self-expandable, a mechanically expandable or a balloon expandable
THV (or a combination of these) with a circular or cylindrical valve frame or stent
that is sized to be expanded and held in the docking device.
[0040] Figs. 6 and 7 show a transseptal procedure for delivering the docking device 1 to
a patient's mitral position, where a guide sheath/introducer 1000 is advanced across
the atrial septum of the heart and a distal end of a delivery catheter 1010 is advanced
through the guide sheath 1000 and positioned with a distal opening of the delivery
catheter positioned in the left atrium for delivering the docking device 1. Optionally,
a delivery catheter can be similarly advanced through the anatomy (e.g., vasculature,
chambers of the hearth, septum, etc.) and similarly positioned without first inserting
or using a guide sheath. In an example procedure, the guide sheath 1000 (and/or delivery
catheter 1010) is introduced into the patient's venous system by percutaneous puncture
or by a small surgical cut, for example, at the patient's groin, and then the guide
sheath 1000 (and/or catheter 1010) is advanced through the patient's vasculature to
the left atrium as shown in Figs. 6 and 7. It is noted that the transseptal procedure
illustrated is only one example, and various alternative procedures and/or access
sites can instead be used for delivering the docking device 1 and/or a suitable prosthetic
valve to either the mitral position or to other positions of the heart. However, a
transatrial or transseptal procedure may be preferable, because such procedures provide
a cleaner entry into the left side of the heart when compared, for example, to a transapical
procedure or other procedure where access to the mitral valve is via the left ventricle,
so that the practitioner can avoid direct interference with the chordae tendineae
and other ventricular obstacles.
[0041] As shown in Fig. 6, the delivery catheter 1010 is advanced to a position in the left
atrium where the distal end of the delivery catheter 1010 is just above a plane of
the native valve (e.g., the mitral plane) and can be positioned, for example, near
a commissure of the native valve. The delivery catheter can be steerable in multiple
dimensions (e.g., more than two dimensions) to allow more precise positioning. The
positioning of the distal opening of the delivery catheter defines an access site
for implanting the docking device 1 at the mitral position. The access site is usually
near one of the two commissures of the native mitral valve, so that the leading tip
21 of the docking device 1 can be advanced through the native valve commissure into
the left ventricle, in order to deploy the leading coil/turn (e.g., ventricular coil)
of the lower region 20, as well as at least part of the functional coils (e.g., coils
of the central region 10), into the left ventricle. In one deployment method, the
leading tip 21 of the docking device 1 is first passed through commissure A3P3 of
the native mitral valve, and then more of the docking device 1 is advanced out of
the delivery catheter through commissure A3P3.
[0042] While the docking device 1 is held in the delivery catheter 1010, the docking device
1 can be straightened to be more easily maneuvered through the delivery catheter 1010.
Thereafter, as the docking device 1 is rotated, pushed or otherwise advanced out of
the delivery catheter 1010, the docking device 1 can return to its original coiled
or curved shape, and further advancement of the docking device 1 out of the delivery
catheter causes either a clockwise or a counter-clockwise (i.e., viewing the annulus
in the direction of blood outflow) advancement of the leading tip 21 around (e.g.,
to encircle) various features of the mitral anatomy, based on the direction of curvature
of the docking device 1 when it exits the delivery catheter. The enlarged leading
coil/turn (e.g., ventricular coil/turn) at the lower region 20 of the docking device
1 makes navigating the leading tip 21 of the docking device 1 around the mitral anatomy
in the left ventricle easier. In the above example, when the leading tip 21 of the
docking device 1 enters the left ventricle through commissure A3P3 and is advanced
clockwise viewing the annulus in the outflow direction (e.g., from atrium to ventricle),
the docking device 1 can first go around and corral the posterior leaflet of the native
mitral valve. Alternative methods are also available for corralling the posterior
leaflet first, for example, by inserting the leading tip 21 through commissure A1P1
and then advancing the docking device counter-clockwise.
[0043] In some situations, corralling of the posterior leaflet of the native mitral valve
first may be easier than corralling of the anterior leaflet first, because the posterior
leaflet is positioned closer to a ventricular wall that provides for a more confined
space along which the leading tip 21 can advance. The leading tip 21 of the docking
device 1 can therefore use the ventricular wall near the posterior leaflet as a pathway
or guide for advancement around the posterior leaflet. Conversely, when trying to
advance the leading tip 21 of the docking device 1 around and to capture the anterior
leaflet of the native mitral valve first, there is no ventricular wall nearby that
can facilitate or guide the advancement of the leading tip 21 in that direction. Therefore,
in some situations, it can be more difficult to properly initiate the encircling of
the mitral anatomy when navigating the leading tip 21 to try to first capture the
anterior leaflet instead of the posterior leaflet.
[0044] With that said, it can still be preferential or required in some procedures to corral
the anterior leaflet first. In addition, in many situations, it can also be much simpler
to bend the distal end of the delivery catheter 1010 in a counter-clockwise direction
in preparation for delivery of the docking device. As such, the delivery method of
the docking device can be adjusted accordingly. For example, a docking device can
be configured with coil turns in an opposite, counter-clockwise direction (e.g., as
seen in Fig. 10 below), where the delivery catheter 1010 also winds in a counter-clockwise
direction. In this manner, such a docking device can be advanced, for example, through
commissure A3P3 and into the left ventricle in a counter-clockwise direction viewing
the annulus in an outflow (e.g., atrium to ventricle) direction instead of in the
clockwise direction described above.
[0045] An amount of the docking device to be advanced into the left ventricle depends on
the particular application or procedure. In one embodiment, the coil(s) of the lower
region 20, and most of the coils of the central region 10 (even if not all) are advanced
and positioned in the left ventricle. In one embodiment, all of the coils of the central
region 10 are advanced into the left ventricle. In one embodiment, the docking device
1 is advanced to a position where the leading tip 21 sits behind the anterior medial
papillary muscle. This position provides a more secure anchoring of the leading tip
21, and consequently of the docking device 1 as a whole, because the leading tip 21
sits and is held between the chordae tendineae and the ventricular wall in that area.
Meanwhile, once any part of the mitral anatomy is corralled and/or captured by the
leading tip 21, further advancement of the docking device 1 serves to gather the captured
chordae and or leaflets within the coils of the docking device 1. Both the secure
positioning of the leading tip 21 and the holding of the native mitral anatomy by
the docking device 1 can serve to prevent obstruction of the left ventricular outflow
tract (e.g., of the aortic valve) prior to implantation of the THV.
[0046] After a desired amount of the docking device 1 has been advanced into the left ventricle,
the rest of the docking device 1 is then deployed or released into the left atrium.
Fig. 7 shows one method of releasing the atrial portion of the docking device 1 into
the left atrium. In Fig. 7, the distal end of the delivery catheter 1010 is rotated
backwards or retracted, while the docking device 1 remains in substantially the same
position and orientation, until the entire docking device 1 is released from the delivery
catheter 1010. For example, when the docking device 1 is advanced clockwise through
commissure A3P3, the distal end of the delivery catheter 1010 can thereafter be rotated
counter-clockwise or retracted for releasing the atrial portion of the docking device
1. In this manner, a ventricular position of the docking device 1 does not have to
be adjusted or readjusted during or after releasing the atrial portion of the docking
device 1 from the delivery catheter 1010. Various other methods of releasing the atrial
portion of the docking device 1 can also be employed. Prior to releasing the stabilization
coil/turn (e.g., atrial coil) from the delivery catheter, it can be held in place
and/or retracted/retrieved by a holding device/anchor (e.g., by being hooked to a
release suture, connected by a barb, a Velcro hook,, a latch, a lock, an anchor that
can screw in to the delivery device, etc.). Once released, the docking device is not
tightly engaged with the native mitral valve (i.e., it is only loosely positioned
around the native mitral valve leaflets).
[0047] After the docking device 1 is fully deployed and adjusted to a desired position and
orientation, the delivery catheter 1010 can be removed to make room for a separate
delivery catheter for delivering the THV, or in some embodiments, the delivery catheter
1010 can be adjusted and/or repositioned if the prosthetic valve is to be delivered
through the same catheter 1010. Optionally, the guide sheath 1000 can be left in place
and the prosthetic valve or THV delivery catheter can be inserted and advanced through
the same guide sheath 1000 after the delivery catheter 1010 is removed. Fig. 8 shows
a cross-sectional view of a portion of a patient's heart with the docking device 1
of Figs. 3 to 5 positioned at the mitral position and prior to delivery of the THV.
Here, the enlarged upper region 30 of the docking device 1 can push against the atrial
walls to help hold the docking device 1 in the desired orientation, and as described
above, the biasing of the upper region 30 can be arranged so that the upper region
30 does not push against any walls that could potentially lead to obstructions in
the left ventricular outflow tract.
[0048] In addition, it should be noted that in at least some procedures, once the docking
device 1 is delivered to the mitral position as described above, and prior to implantation
of the prosthetic valve therein, the native mitral valve can still continue to operate
substantially normally, and the patient can remain stable, since the valve leaflets
are not substantially restrained by the docking station. Therefore, the procedure
can be performed on a beating heart without the need for a heart-lung machine. Furthermore,
this allows the practitioner more time flexibility to implant the valve prosthesis,
without the risk of the patient being in or falling into a position of hemodynamic
compromise if too much time passes between the implantation of the docking device
1 and the later valve implantation.
[0049] Fig. 9 shows a cross-sectional view of a portion of the heart with both the docking
device 1 and a prosthetic valve 40 (e.g., THV) finally implanted at the mitral position.
Generally, the prosthetic valve 40 will have an expandable frame structure 41 that
houses a plurality of valve leaflets 42. The expandable frame 41 of the prosthetic
valve 40 can be balloon expandable, or can be expanded in other ways, for example,
the frame can be self-expanding, mechanically-expanding, or expandable in a combination
of ways. The prosthetic valve 40 can be delivered through the same catheter 1010 used
to deliver the docking device 1, or can be introduced through a separate catheter,
generally while the valve 40 is radially collapsed for easier navigation through the
delivery catheter. Optionally, the guide sheath can be left in place when catheter
1010 is removed, and a new prosthetic valve or THV delivery catheter can be advanced
through guide sheath 1000. The prosthetic valve 40 is then advanced out of the delivery
catheter and positioned through the docking device 1 while still in the collapsed
configuration, and can then be expanded in the docking device 1, so that the radial
pressure or tension between the components securely hold the entire assembly in place
at the mitral position. The mitral valve leaflets (or a portion of the mitral valve
leaflets) can be sandwiched between the functional turns of the docking coil and the
frame 41 of the prosthetic valve. After the docking device and prosthetic valve are
securely deployed/implanted, the remaining delivery tools can be removed from the
patient.
[0050] Fig. 10 shows a perspective view of a modified version of the coil anchor or docking
device 1 of Figs. 3 to 5. The docking device 100 in Fig. 10 has a central region 110,
a lower region 120, and an upper region 130 that can be the same as or similar to
the respective central, lower, and upper regions 10, 20, 30 in the previously described
docking device 1. The docking device 100 can include features and characteristics
that are the same as or similar to features and characteristics described with respect
to docking device 1, and can also be implanted using the same or similar steps. However,
the docking device 100 includes an additional extension 140 substantially positioned
between the central region 110 and upper region 130. In some embodiments, the extension
140 can optionally be positioned, for example, wholly in the central region 110 (e.g.,
at an upper portion of the central region 110) or wholly in the upper region 130.
In Fig. 10, the extension 140 is made up of or includes a vertical part of the coil
that extends substantially parallel to a central axis of the docking device 100. In
some embodiments, the extension 140 can be angled relative to the central axis of
the docking device 100, but will generally serve as a vertical or axial spacer that
spaces apart the adjacent connected portions of the docking device 100 in a vertical
or axial direction, so that a vertical or axial gap is formed between the coil portions
on either side of the extension 140 (e.g., a gap can be formed between an upper or
atrial side and a lower or ventricular side of the docking device 100).
[0051] The extension 140 of the docking device 100 is intended to be positioned through
(e.g., crossing) or near the native valve annulus, in order to reduce the amount of
the docking device 100 that passes through or pushes or rests against the native annulus
when the docking device 100 is implanted. This could potentially reduce the stress
or strain applied by the docking device 100 on the native mitral valve. In one arrangement,
the extension 140 is positioned at and passes through or crosses at one of the commissures
of the native mitral valve. In this manner, the extension 140 can space the upper
region 130 apart from native mitral leaflets to prevent the upper region 130 from
interacting with or engaging the native leaflets from the atrial side. The extension
140 also raises a position of the upper region 130, so that the contact that the upper
region 130 makes against the atrial wall can be elevated or spaced farther away from
the native valve, which could, for example, also reduce stresses on and around the
native valve, as well as provide for a more secure holding of the position of the
docking device 100. The extension 140 can have a length ranging from 5 to 100 mm,
and in one embodiment is 15 mm.
[0052] The docking device 100 can further include one or more through holes 150 at or near
one or both of the proximal and distal ends of the docking device 100. The through
holes 150 can serve, for example, as suturing holes for attaching a cover layer over
the coil of the docking device 100, and/or for example, as an attachment site for
delivery tools, such as a pull wire/suture for a pusher, a holding device/anchor (e.g.,
for holding the docking device and/or allowing retraction and retrievability of the
device after being fully or partially deployed from the delivery catheter), or other
advancement device or retention device. In some embodiments, a width or thickness
of the coil of the docking device 100 can also be varied along the length of the docking
device 100. For example, a central region of the docking device 100 can be made slightly
thinner than end regions of the docking device 100 (not shown), so that for example,
the central regions exhibit greater flexibility, the end regions are stronger or more
robust, and/or the end regions provide more surface area for suturing or otherwise
attaching a cover layer to the coil of the docking device 100, among other reasons.
In one embodiment, all or a portion of extension 140 can have a thickness that is
less than the thickness in other regions of the docking device, e.g., extension 140
can be thinner than the leading coil/turn or lower region 120, thinner than the functional
coils/turns or central region 110, and/or thinner than the stabilization coil/turn
or upper region 130, e.g., as shown, for example, in Fig. 19.
[0053] In Fig. 10 (and similarly Fig. 19), the coils of the docking device 100 are depicted
as turning in a direction opposite to the coils in the docking device 1 described
above. Therefore, the docking device 100, as depicted, is configured to be inserted
through the native valve annulus in a counter-clockwise direction viewing the annulus
in the direction of blood outflow (e.g., from atrium to ventricle). This advancement
can be made through commissure A3P3, commissure A1P1, or through another part of the
native mitral valve. Arrangement of the docking device 100 in a counter-clockwise
direction also allows for bending of the distal end of the delivery catheter in a
similar counter-clockwise direction, which in many instances is easier to achieve
than to bend the delivery catheter in the clockwise direction. The various coiled
docking device embodiments described herein (including docking devices 1, 100, 200,
300, 400, 500, 600, and 1100) can be configured for either clockwise or counter-clockwise
advancement through one of various access points (e.g., either commissure).
[0054] In most situations and patients, the docking device should be placed high relative
to the native mitral valve (e.g., farther into the left atrium). When considering
the mitral anatomy, the finally implanted dock and valve combination should be placed
high at the native valve, in some cases as high as possible, to anchor the valve to
a clear zone of the native mitral leaflets. In addition, in a healthy human heart,
the native mitral leaflets are generally smoother above the coaptation line (e.g.,
above where the leaflets come together when the mitral valve is closed) and rougher
below the coaptation line. The smoother area or zone of the native leaflets are much
more collagenous and stronger, thereby providing a more secure anchoring surface for
the prosthetic valve than the rougher area or zone. Therefore, in most cases, the
docking device should be placed as high as possible at the native valve during insertion,
while also having sufficient retention force to anchor the prosthetic valve or THV.
For example, the length of the coil in the docking device placed in the ventricle
generally depends on the number of turns in the ventricle and the thickness of the
wire used. Generally, the thinner the wire used, the more length is required in the
ventricle to provide sufficient retention force. For example, if a docking device
coil has a length of 370 mm, then about 280 mm (e.g., ±2 mm) would be placed in the
ventricle. About 70 to 90 mm would be placed in the atrium, and about 10-15 would
be used in the transition or extension length to move the docking device coils away
from the plane of the mitral valve on the atrial side of the docking device.
[0055] The average mitral valve in humans measures approximately 50 mm along its long axis
and 38 mm along its short axis. Due to the size and shape of the native valve and
the typically smaller size of replacement valves, an inverse relationship is formed
with respect to the coil diameter of the docking device between how high the docking
device can be placed at the mitral position and the retention force the docking device
can provide for the THV to be implanted therein. Docking devices with larger diameters
are able to capture more chordae therein and consequently have the ability to be deployed
higher relative to the native valve, but will provide a lower amount of retention
force for valves that are docked in them. Conversely, docking devices with smaller
diameters can provide stronger retention forces for docked valves, but may not be
able to go around and capture as many chordae during positioning, which can result
in lower positioning of the docking device in the native valve annulus. Meanwhile,
larger docking devices can be modified so that they have increased coil diameters
or thicknesses and/or can be constructed using materials with higher moduli of elasticity.
[0056] Figs. 11 to 13 show a docking device according to another embodiment of the invention.
The docking device 200 (see Figs. 12 and 13) is formed with a laser-cut tube 210 and
a tensioning wire 219. The wire 219 can be used to adjust the curvature and/or size
of the docking device 200. For example, the docking device 200 can assume a larger
or wider configuration when being positioned at the native valve annulus, and can
thereafter be adjusted with the wire 219 to assume a smaller or narrower configuration
to prepare for docking a prosthetic valve.
[0057] Fig. 11 schematically shows an open sheet view of a laser-cut tube 210, e.g., the
ends of the sheet can be connected to form a tubular structure, or a similar tube
can be formed as a tube and cut as a tube, i.e., without a seam. The tube 210 can
be made from either shape memory or non-shape memory material (e.g., NiTi, stainless
steel, other materials, or a combination of materials). The tube 210 can be laser
cut with the pattern shown in Fig. 11, or with a similar pattern, where the cutting
pattern dictates the shape of the docking device 200 when the docking device 200 is
actuated. The patterned cuts in Fig. 11 include a plurality of separate cuts 211 that
extend transversely to a longitudinal axis of the tube 210, and that separate the
tube 210 into a plurality of interconnected links 212. Each of the cuts 211 can further
form one or more teeth 213 and one or more corresponding grooves 214 in adjacent links
212, where the teeth 213 can extend into the adjacent grooves 214, including when
the tube 210 is bent or curved. The teeth 213 and grooves 214 formed by each cut 211
can extend in a same direction along the tube 210, or some can be configured to extend
in the opposite direction, depending on the desired shape of the docking device 200.
The cuts 211 are also wholly contained on the sheet or tube, in other words, the cuts
211 do not extend to any of the edges of the tube sheet or tube, so that the links
212 remain interconnected with one another at least at one region. In other embodiments,
some or all of the cuts can extend to the edges of the sheet or tube, as needed. In
the embodiment of Fig. 11, each of the cuts 211 further include end regions 215 on
either end of the cuts 211 that extend parallel to the longitudinal axis of the tube
210. The end regions 215 provide space for adjacent links 212 to pivot relative to
one another while remaining interconnected.
[0058] The laser-cut patterning can also be modified or varied along the length of the tube
210, with cuts having different sizes, shapes, and positioning on the sheet or tube,
in order to effect different shapes and curvatures in the docking device 200 when
the docking device 200 is tensioned or actuated. For example, as seen in Fig. 11,
a left end of the sheet or tube includes other cuts 216 that are larger than cuts
211 that are found at the central and right portions of the sheet or tube (as illustrated).
The left end of the tube 210 can have such enlarged laser cut patterns in order to
effect a more mobile or flexible distal tip of the docking device 200, as described
in greater detail below.
[0059] In addition, the laser-cut sheet or tube can include one or more distal wire lock
features, for example, cut 217 at a distal or left end of the sheet or tube as illustrated,
and/or one or more proximal wire lock features, for example, cuts 218 at the proximal
or right end of the sheet or tube as illustrated. Using one or both of the distal
217 or proximal 218 wire lock features, a locking wire 219, illustrated in Fig. 11A,
can be attached to the distal or proximal end of the tube 210, and can then be tensioned
through the tube 210 and locked at the opposite end of the tube 210 in order to effect
a desired actuated shape of the docking device 200. By having laser cut patterns positioned
along a large portion of or along the entire length of the tube 210, when the locking
wire 219 is attached at one end of the tube 210 and is then actuated and locked to
the other end of the tube 210, the tube 210 is forced into a desired final coil form
or shape by virtue of the arrangement of the cuts 211 and 216. The tension in the
tensioning wire has the ability to control the radial outward and inward forces applied
onto the docking device 200, and by the docking device 200 onto other features, for
example, on a replacement valve 40 held therein. The locking wire can assist in controlling
the forces applied by the docking device, but in other embodiments, a locking wire
is not required. The locking wire can be in a laser-cut hypotube, or the locking wire
can be in a tube that is not laser cut. The locking wire can be a suture, tether,
wire, strip, etc., and the locking wire can be made of a variety of materials, e.g.,
metal, steel, NiTi, polymer, fiber, Dyneema, other biocompatible materials, etc.
[0060] In some embodiments, for example, embodiments where a shape memory material, such
as NiTi, is used to construct the docking device 200, the tube 210 can be placed around
a round mandrel defining a desired coil diameter during manufacture and shape set
at that specific diameter. The shape set diameter can in some embodiments be larger
than the desired final diameter of the docking device 200, so that the tube 210 assumes
the larger shape set diameter when it is extruded from a delivery catheter and prior
to the locking or tensioning wire being actuated. During this time, the larger diameter
of the docking device 200 can help assist the docking device 200 in more easily navigating
around and encircling the anatomical geometry of the native valve.
[0061] Furthermore, in some embodiments, the distal tip 222 of the tube 210 can be shape
set differently, so that instead of following the same coil shape as the rest of the
docking device 200, the distal tip 222 flexes or articulates slightly radially outwardly
compared to other portions of the docking device 200, for example, as can be seen
in Fig. 12, in order to further assist in helping to encircle the mitral anatomy or
other valve anatomy. In addition to or in lieu of a different shape setting, as mentioned
above, the distal end 222 of the tube 210 can include different cuts 216 in order
to make the distal end 222 more flexible or mobile, which can also assist in navigating
the distal end 222 of the docking device 200 around the anatomical geometry.
[0062] After the docking device 200 has been maneuvered around the mitral anatomy or other
anatomical geometry and has reached a desired position relative to the native valve,
the locking wire can be tensioned or otherwise actuated in order to reduce the size
of the docking device (e.g., to reduce the diameter of the turns of the coil), in
preparation for a tighter or more secure docking of a prosthetic replacement valve
40. Meanwhile, in some embodiments where the distal tip 222 of the docking device
200 is shape set to flex outwards, the tensioning of the locking wire can in some
cases draw or pull the distal tip 222 further inwards such that the distal tip 222
conforms more closely in shape to the rest of the docking device 200, to more effectively
contribute to the docking of the replacement valve 40.
[0063] Thereafter, the replacement valve 40 can be positioned and expanded in the docking
device 200. Fig. 13 is an example of the docking device 200 after it has been actuated
by the locking wire, and also after the replacement valve 40 has been expanded therein.
The tension in the locking wire helps to more effectively hold a desired shape and
size of the docking device 200 and to maintain a stronger retention force between
the docking device 200 and the valve 40. The radial outward pressure provided by the
valve 40 on the docking device 200 is countered by the radial inward pressure provided
by the tensioning or locking wire and docking device 200 onto the valve 40, forming
a stronger and more secure hold between the pieces. As can further be seen in Fig.
13, since the docking device 200 can more effectively hold its shape and size, the
radial inward pressure from the docking device 200 on the valve 40 can cause a flaring
effect at the ends of the frame of the valve 40, thereby providing an even more secure
hold between the docking device 200 and the valve 40.
[0064] The docking device 200 can be modified in various ways in other embodiments. For
example, the docking device can be made from or include shape memory materials other
than NiTi, or in some embodiments can be made from non-shape memory materials, such
as stainless steel, from other biocompatible materials, and/or a combination of these.
In addition, while the docking device 200 has been described above for use at the
mitral valve, in other applications, a similar or slightly modified docking device
can also be used to dock replacement valves at other native valve sites, for example,
at the tricuspid valve, pulmonary valve, or at the aortic valve.
[0065] The docking device 200 described above, and similar devices using a tensioning or
locking wire, can provide several advantages over other docking devices, such as devices
where a locking wire is not used. For example, the locking wire provides a user with
the ability to control an amount of the radial outward and inward forces applied on
and by the docking device through effecting and adjusting the tension in the locking
wire, without compromising a desired profile of the docking device or the ability
to deliver the docking device through a catheter or via minimally invasive techniques.
Figure 11A illustrates a tensioning wire 219 that is held below the teeth 218 or looped
around teeth 218, then pulled through the opening 217 and crimped at the opening 217
to set the shape of the docking device. In addition, the laser cuts in the tube make
the docking device more flexible, enabling the docking device to be introduced through
catheters that may have relatively small bend radii at certain locations.
[0066] In embodiments where a shape memory material is used, the docking device can be shape
set to a coil having a larger diameter to allow the coil to more easily encircle anatomical
features during delivery of the docking device and prior to the locking wire being
tensioned. In addition, the distal tip of the docking device can further be shape
set to flex or bias slightly outwards to help encircle even more of the anatomical
geometry during advancement and positioning of the docking device. In addition, in
some embodiments, the distal tip of the docking device can further be modified, for
example, with more material removed to form larger cuts, making the distal portion
of the docking device even more flexible, so that the tip can more easily be actuated
and manipulated to more effectively navigate it around and encircle different cardiovascular
anatomies. A pattern can be laser cut to reduce the forces more in one area than another.
The tube can be ovalized, that is the cross-section area of the tube can be ovalized,
so that the forces allow the tube to curve in a desired direction. The tensioning
wire can also be clamped at both a proximal and a distal end of the tube, to provide
a tensioning force. Exemplary cut patterns are illustrated, but other cut patterns
are also possible.
[0067] Various mechanisms can further be incorporated or added to one or more of the docking
devices described herein (e.g., herein docking devices 1, 100, 200, 300, 400, 500,
600, and 1100), for example, in order to increase the retention force between the
docking device and a replacement valve that is expanded therein. Generally, coil-shaped
docking devices will have two open or free ends after implantation. When a THV or
other replacement valve is expanded in the coil, the coil can partially unwind and
increase in diameter due to the outward pressure applied by the expanding valve on
the coil, which in turn reduces the retention force applied by the coil on the valve.
Mechanisms or other features can therefore be incorporated into the docking devices
to prevent or reduce unwinding of the coil when the replacement valve is expanded
in it, resulting in an increase in radial forces and retention forces between the
docking device and the valve. Such mechanisms can be incorporated in lieu of modifying
the size and shape of the docking device, for example, without making the coil thicker
or reducing the diameter of the inner space formed by the coil, both of which can
negatively affect the performance or ease of delivery of the docking device. For example,
when the coil of the docking device itself is made thicker, the increased thickness
results in a more rigid coil, making it more difficult to pass the docking device
through a delivery catheter. Meanwhile, when the diameter of the inner space formed
by the coil is reduced too much, the reduced space can prevent the expandable valve
from fully expanding.
[0068] A first alternative modification to ensure sufficient retention force between a docking
device and a valve that is expanded in the docking device is shown in Fig. 14. The
docking device 300 in Fig. 14 includes a main coil 310 (which can be similar in size
and shape to one of the docking devices described above) and anchors 320 extending
from the two free ends of the coil 310. The anchors 320 are sized, shaped, or otherwise
configured to embed themselves into the surrounding tissue (e.g., into the atrial
and/or ventricular walls), for example, when a replacement valve is expanded in the
docking device 300. The anchors 320 can be barbed to promote ingrowth once the anchors
320 are embedded into the heart walls or other tissue. The anchors can be any of many
different shapes and sizes. The anchors can extend from the end or from any area near
the end. Optionally, anchors or barbs can also be positioned at various locations
along the length and outer surface of the docking device.
[0069] In operation, when the docking device 300 is deployed at the mitral anatomy, once
the docking device 300 is positioned through the mitral valve, one end of the docking
device 300 is positioned in the left atrium while the other end of the docking device
300 is positioned in the left ventricle. The shape and size of the coil 310 of the
docking device 300 can be selected and optimized to ensure that the ends of the coil
310 respectively abut against the atrial and ventricular walls when the docking device
300 is advanced to the desired position. The anchors 320 at the ends of the coil 310
can therefore anchor themselves into the respective heart walls. When the replacement
valve is expanded in the coil 310, the free ends of the coil 310 are held in position
by the anchors 320 being lodged in the heart walls. The inability of the free ends
of the coil 310 to move when the replacement valve is expanded in the docking device
300 prevents the coil 310 from unwinding, thereby increasing the radial forces applied
between the docking device 300 and the expanded valve and improving the retention
force between the components.
[0070] Fig. 15 shows a schematic view of a portion of another modified docking device for
improving retention forces between the docking device and a replacement valve. Portions
of three turns of a docking device 400 are illustrated in Fig. 15. The docking device
400 includes a main coil or core 410, which can be for example, a NiTi coil/core,
or a coil/core that is made of or includes one or more of various other biocompatible
materials. The docking device 400 further includes a covering 420 that covers the
coil/core 410. The covering 420 can be made of or include a high friction material,
so that when the expandable valve is expanded in the docking device 400, an increased
amount of friction is generated between the valve and the covering 420 to hold a shape
of the docking device 400 and prevent or inhibit/resist the docking device 400 from
unwinding. The covering can also or alternatively increase the amount of friction
between the docking device and native leaflets and/or the prosthetic valve to help
retain the relative positions of the docking device, leaflets, and/or prosthetic valve.
[0071] The covering 420 is made from one or more high friction materials that is placed
over the coil wire 410. In one embodiment, the covering 420 is made of or includes
a PET braid over an ePTFE tube, the latter of which serves as a core for the covering
420. The ePTFE tube core is porous, providing a cushioned, padded-type layer for struts
or other portions of a frame of the expandable valve to dig into, improving engagement
between the valve and the docking device 400. Meanwhile, the PET layer provides additional
friction against the native valve leaflets when the prosthetic valve is expanded and
the struts or other portions of the valve frame apply outward pressure on the docking
device 400. These features can work together to increase radial forces between the
docking device 400 and the native leaflets and/or prosthetic valve, thereby also increasing
retention forces and preventing the docking device 400 from unwinding.
[0072] In other embodiments, the covering 420 can be made from one or more other high friction
materials that covers the coil 410 in a similar manner. The material or materials
selected for making the covering 420 can also promote rapid tissue ingrowth. In addition,
in some embodiments, an outer surface of a frame of the replacement valve can also
be covered in a cloth material or other high friction material to further increase
the friction force between the docking device and the valve, thereby further reducing
or preventing the docking device from unwinding. The friction provided by the covering
can provide a coefficient of friction greater than 1. The covering can be made of
ePTFE and can be a tube that covers the coil, and can be smooth or can have pores
(or be braided or have other structural features that provide a larger accessible
surface area like pores do) to encourage tissue ingrowth. The covering can also have
a PET braid over the ePTFE tube when the ePTFE tube is smooth. The outermost surface
of the covering or braid over the covering can be any biocompatible material that
provides friction, such as a biocompatible metal, silicone tubing, or PET. Pore size
in the covering can range from 30 to 100 microns. In embodiments where there is a
PET covering on top of the ePTFE, the PET layer is only attached to the ePTFE covering,
and not directly to the coil of the docking device. The ePTFE tube covering can be
attached to the docking device coil at the coverings proximal and distal ends. It
can be laser welded on to the coil, or radiopaque markers can be placed on the outside
of the ePTFE tube covering or PET braid and swaged to the materials to hold them in
place to the coil.
[0073] Meanwhile, in some embodiments, the docking device 400 can also include anchors similar
to anchors 320 discussed above to further increase retention forces, but other embodiments
of the docking device may incorporate the covering 420 without further including any
such additional end anchors. Once the replacement valve is expanded in the docking
device 400 and the resulting assembly begins functioning as a combined functional
unit, any tissue ingrowth can also serve to reduce the load on the combined valve
and dock assembly.
[0074] The covering 420 can be added to any of the docking devices described herein (e.g.,
docking devices 1, 100, 200, 300, 400, 500, 600, and 1100) and can cover all or a
portion of the docking device. For example, the covering can be configured to only
cover the functional coils, the leading coil, the stabilization coil, or just a portion
of one or more of these (e.g., just a portion of the functional coils)
[0075] Figs. 16 and 16A schematically show a portion of yet another modified docking device
that improves retention forces between the docking device and a replacement valve.
As is illustrated in the sectional view of Fig. 16A, the valve leaflet tissue 42 undulates
to conform to the varying cross-section between the areas of the coil 510 with frictional
elements 510 and without the frictional elements. This undulating of the leaflet tissue
42 results in a more secure entrapment of the tissue 42 between the docking device
1 and the valve frame 41. The docking device 500 in Fig. 16 includes a main coil 510
and one or more discrete friction elements 520 that are spaced apart along a length
of the coil 510. The friction elements 520 can be made from a cloth material or other
high friction material, such as PET, and can be formed as small bulges on the surface
of the coil 510 or on another layer that is placed on the coil 510. In some embodiments,
the covering 420 can itself be considered a frictional element or be configured to
form one or more of the frictional elements 520. In some embodiments, the friction
elements 520 are added on top of adding a high friction covering 530 that is similar
to the covering 420 discussed above. An example of a docking device 500 with both
a high friction covering 530 and friction elements 520 applied over a main coil 510
is schematically illustrated in Fig. 17.
[0076] When an expandable valve is expanded in the docking device 500, friction is formed
between the frame of the valve and the friction elements 520 and/or between the frame
of the valve, the native valve leaflets, and the docking devicethat prevents or inhibits/resists
the coil 510 of the docking device 500 from unwinding. For example, the friction elements
520 can engage or otherwise extend into cells defined by the frame of the expandable
valve and/or force valve leaflet tissue into cells of the expandable valve. In addition,
when the valve is expanded in the docking device 500, each of the friction elements
520 can engage with adjacent turns of the docking device 500 above and/or below the
friction element 520, and/or with one or more other friction elements 520 on the adjacent
turns of the docking device 500. Any or all of these such engagements will cause the
docking device 500 to inhibit or resist unwinding, thereby increasing the retention
force between the docking device 500 and the expanded valve.
[0077] Fig. 18 schematically shows parts of three turns of still another modified docking
device 600 that helps improve retention forces between the docking device and a replacement
valve. The docking device 600 includes a coil 610 that is modified with one or more
interlocking lock and key patterns spaced apart along the length of the coil 610.
The lock and key patterns can be simple, for example, a rectangular groove or cutout
618 and a complementary rectangular projection 622, as generally illustrated in Fig.
18, or can be made of or include different shapes and/or more complex patterns in
other embodiments. In addition, the grooves 618 and projections 622 can all be arranged
in a same axial direction or in different axial directions in varying embodiments.
The lock and key patterns or other frictional elements can be placed on the functional
turns of the docking device.
[0078] When an expandable valve is expanded in the docking device 600, the lock and key
mechanism relies on adjacent turns of the coil 610 abutting against one another and
on each turn interlocking with adjacent turns of the coil 610 located above and/or
below it when one or more of the projections 622 engage corresponding grooves 618.
The interlocking of the grooves 618 and the projections 622 prevents relative motion
between the respective features, consequently also preventing the coil 610 of the
docking device 600 from physically unwinding. Therefore, this arrangement also serves
to increase the radial forces and the final retention force between the docking device
600 and a replacement valve that is expanded in the docking device 600.
[0079] Fig. 19 shows a perspective view of an exemplarycoil anchor or docking device. The
docking device 1100 in Fig. 19 can be the same as or similar in structure to the docking
device 100 in Fig. 10 described above and can include any of the features and characteristics
described with respect to docking device 100. Docking device 1100 can also include
a central region 1110, a lower region 1120, an upper region 1130, and an extension
region 1140. The lower and upper regions 1120, 1130 can form larger coil diameters
than the central region 1110, and the extension region 1140 can space the upper region
1130 apart from the central region 1110 in a vertical direction, also similarly as
previously described. The docking device 1100 is also arranged or wound so that advancement
of the docking device 1100 into the left ventricle can be performed in a counter-clockwise
manner viewing the annulus in the outflow direction (e.g., from atrium to ventricle).
Other embodiments may instead facilitate clockwise advancement and placement of the
docking device.
[0080] In the embodiment in Fig. 19, the central coils/turns 1110 of the docking device
1100 also serve as the functional coils/turns, and provide a main docking site for
a prosthetic valve or THV that is expanded therein. The central turns 1110 will generally
be positioned in the left ventricle, while a small distal portion, if any, will extend
through the native valve annulus and into the left atrium, described in greater detail
below. In examples where a THV has a 29 mm expanded outer diameter, the central turns
1110 can have an inner diameter ranging from 20 mm to 30 mm, and in an exemplary embodiment
can be approximately 23 mm (e.g., ±2 mm), in order to provide about 16 N of retention
force between the parts, which is sufficient for stabley holding the expanded THV
in the docking device 1100, and preventing the THV from dislodging from the docking
device 1100, even during severe mitral pressures.
[0081] Meanwhile, the lower region 1120 of the docking device 1100 serves as a leading coil/turn
(e.g., a ventricular encircling turn). The lower region 1120 includes the distal tip
of the docking device 1100, and flares radially outwardly from the central turns 1100,
in order to capture the native valve leaflets, and some or all of the chordae and/or
other mitral anatomy, when the docking device 1100 is advanced into the left atrium.
Native mitral valves exhibiting mitral regurgitation typically measure about a 35
mm A2P2 distance and a 45 mm distance from commissure to commissure. Therefore, when
a THV that is 29 mm is used, the small size of the THV, and consequently the size
of the central turns 1110, are smaller than the long axis of the mitral anatomy. As
such, the lower region 1120 is formed to have an enlarged size or profile compared
to the central turns 1110, in order to initially guide the docking device 1100 more
easily around both of the native valve leaflets. In one example, the diameter of the
lower region 1120 can be constructed to be about the same as the distance measured
between the commissures of the native valve (e.g., 45 mm), such that the distal tip
will extend approximately that distance away from the outlet of the delivery catheter
during delivery of the docking device 1100.
[0082] The upper region 1130 of the docking device 1100 serves as the stabilization coil/turn
(e.g., atrial coil/turn) that provides the docking device 1100 with a self-retention
mechanism during the transition phase after the docking device 1100 is deployed at
the native valve and prior to delivery of the THV. The left atrium generally flares
outwardly from the mitral annulus, forming a funnel-like shape that widens away from
the annulus. The diameter of the upper region 1130 is selected to allow the upper
region 1130 to fit at an approximate desired height in the left atrium, and to prevent
the upper region 1130 from sliding or dropping further towards the native mitral annulus
after the desired position is achieved. In one example, the upper region 1130 is formed
to have a diameter from 40-60 mm, such as a diameter of about 53 mm.
[0083] In addition, the shape and positioning of the upper region 1130 are selected such
that after the THV is expanded in the docking device 1100, the upper region 1130 applies
minimal or no pressure to the portion of the atrial wall that is adjacent to the aortic
wall. Fig. 20 is a schematic top view of a portion of a heart, showing an approximation
of the left atrium 1800, and the mitral valve 1810 positioned at a central region
thereof. In addition, an approximate position of the aorta 1840 is also schematically
illustrated. Meanwhile, a docking device 1100 has been delivered to the native mitral
valve 1810 at commissure A3P3 1820. Of note here, the upper region 1130 of the docking
device 1100 is positioned away from a wall 1830 of the left atrium 1800 that is adjacent
to the aorta 1840. Furthermore, when the THV is expanded in the docking device, the
central region 1110 of the docking device 1100 will tend to slightly expand and unwind,
which can further draw the upper region 1130 away from the atrial wall 1830 (e.g.,
counter-clockwise and downward as illustrated in Fig. 20). Additional details of the
positioning of the docking device 1100 relative to the mitral valve 1810, with further
reference to Fig. 20, will be discussed in greater detail below.
[0084] The extension region 1140 provides a vertical extension and spacing between the central
region 1110 and the upper region 1130 of the docking device 1100. In some embodiments,
the extension region 1140 of the docking device 1100 (and extension 140 of docking
device 100) can therefore be referred to as an ascending turn. The location at which
the docking device 1100 crosses the mitral plane is important in preserving the integrity
of the native valve anatomy, and specifically the valve leaflets and commissures,
to serve as an appropriate docking site for the final implantation of the THV. In
docking devices without such an extension or ascending region 1140, more of the docking
device would sit on or against the mitral plane and pinch against the native leaflets,
and the relative motion or rubbing of the docking device against the native leaflets
could potentially damage the native leaflets from the atrial side. Having an extension
region 1140 allows the portion of the docking device 1100 that is positioned in the
left atrium to ascend away and be spaced apart from the mitral plane.
[0085] In addition, the extension region 1140 of the docking device 1100 can also have a
smaller diameter cross-section. In the embodiment shown, the wire core of other regions
of the docking device 1100 can have a diameter of, for example, 0.825 mm, while the
core of the extension region 1140 can have a diameter of 0.6 mm. In another embodiment,
the wire core of other regions of the docking device has a cross section diameter
of 0.85 mm, and the extension region has a cross-section diameter of 0.6 mm. When
the other regions of the docking device coil have a cross-section diameter of 0.825
mm or greater, or a cross-section diameter of 0.85 mm or greater, the extension region
1140 can have a cross-section diameter of 0.4 to 0.8 mm. The thicknesses can also
be chosen based on a ratio to one another. The extension region can have a cross-section
diameter that is 50% to 75% of the cross-section diameter of the rest of the portions
of the wire. An extension region 1140 with a smaller cross-section can allow for a
sharper angle of ascension of the extension region 1140 from the mitral plane. The
radius of curvature and the wire cross-section of the extension region 1140 can further
be selected, for example, to provide a sufficient connection point between the central
region 1110 and the upper region 1130 of the docking device 1100, and/or to allow
the extension region 1140 to be deployed and retrieved more easily with smaller forces
during delivery, since a thinner wire core is generally easier to straighten and bend.
In addition, in embodiments where a shape memory such as NiTi is used for the wire
core, the thicknesses of both the extension region 1140 and the rest of the docking
device 1100 should be chosen so as not to exceed any strain limits, based on the material
properties of the material or materials selected.
[0086] While as noted above, a wire core of the docking device 1100 can be made of NiTi,
another shape memory material, or another biocompatible metal or other material, the
wire core can be covered by one or more additional materials. These cover or layer
materials can be attached in a variety of ways including, for example, adhesion, melting,
molding, etc. around the core or otherwise suturing, tying, or binding the cover/layer
to the wire core. Referring briefly to Fig. 22, a cross-section of a distal portion
of the docking device 1100 includes a wire core 1160 and a cover layer 1170. The wire
core 1160, for example, can provide strength to the docking device 1100. Meanwhile,
a base material of the cover layer 1170 which covers the wire core 1160 can be, for
example, ePTFE or another polymer. The cover layer 1170 can be more compressive than
the wire core 1160, so that the wire frame and/or struts of the THV can partially
dig into or otherwise anchor into the cover layer 1170 for added stability when the
THV is expanded in the docking device 1100. A more compressible material will also
allow the pinching or compression of the native valve leaflets and other anatomy between
the docking device 1100 and the THV to be less traumatic, leading to less wear and/or
damage to the native anatomy. In the case of ePTFE, the material is also not water
or blood permeable, but will allow ethylene oxide gas to pass or penetrate through,
thereby providing a layer through which the underlying wire core 1160 can be more
easily sterilized. Meanwhile, while not blood permeable, an ePTFE cover layer 1170
can be constructed with, for example, a 30 micron pore size, to facilitate easy anchoring
of blood cells in and against the outer surface of the cover layer 1170, for example,
to promote in-growth of tissue after implantation. Furthermore, ePTFE is also a very
low friction material. A docking device 1100 with an ePTFE cover layer 1170 will provide
for stability and promote in-growth.
[0087] While a low friction ePTFE cover layer 1170 can help with interactions between the
ends of the docking device 1100 and the native heart anatomy, additional friction
may be more desirable in the central region 1110, which provides the functional coils
of the docking device 1100 for docking the THV. Therefore, as seen in Fig. 19, an
additional covering 1180 (which can, optionally, be the same as or similar to covering
420 and/or friction elements 520) can be added to the central region 1110 of the docking
device 1100, on top of the ePTFE layer 1170. Fig. 19A illustrates a cross-section
view of the layers. The covering 1180 (depicted as a braided layer) or other high
friction layer provides additional friction between adjacent coils and against the
native leaflets and/or THV when the THV is expanded in the docking device 1100. The
friction that is formed at the interfaces between coils and between the inner surface
of the central region 1110 of the docking device 1100, the native mitral leaflets,
and/or the outer surface of the THV creates a more secure locking mechanism to more
strongly anchor the THV and the docking device 1100 to the native valve. Since the
functional coils/turns or central region 1110 of the docking device 1100, that is,
the region of the docking device that interacts with the THV, is generally the only
region where a high friction covering/layer is desired, as seen in Fig. 19, the braid
layer or high friction covering/layer 1180 does not extend into either the lower region
1120 or the extension region 1140, so that those regions of the docking device 1100,
along with the upper region 1130, remain low friction, in order to facilitate less
traumatic interactions with the native valve and other heart anatomy. Additional friction
elements and thus improvement in retention forces between the docking device and a
replacement valve, can also be added to the device through any combination of the
high friction covering/layer 1180 and high friction elements or other features described
herein and illustrated in Figs. 15-18.
[0088] Fig. 20 shows a top view of a possible placement of the docking device 1100 at the
native mitral valve 1810 prior to expansion of a THV therein. In this embodiment,
the docking device 1100 is advanced counterclockwise through commissure A3P3 1820
of mitral valve 1810 and into the left ventricle. When a desired amount of the docking
device 1100 (e.g., the lower region 1120 and much of the central region 1110) has
been advanced into the left ventricle, the remaining turns of the docking device 1100,
for example, any remaining part of the central region 1110 (if any), the extension
region 1140 (or a portion thereof), and the upper region 1130, is then released from
the delivery catheter, for example, by a clockwise or opposite rotation of the delivery
catheter, such that these parts of the docking device 1100 can be unsheathed or otherwise
released while a position of the central region 1110 and the lower region 1120 of
the docking device 1100 remains stationary or substantially in position relative to
the surrounding anatomy. In Fig. 20, portions of device 1100 below the native valve
are depicted with dotted lines.
[0089] A correct positioning of the docking device 1100 can be very important. In one embodiment,
the docking device 1100 should be positioned relative to the native valve 1810 such
that a desired part of the docking device 1100 extends through the native valve 1810
at or near commissure A3P3, and comes into contact with the atrial side of the native
leaflets. As can be seen, for example, in Fig. 19, a proximal portion of the central
region 1110 of the docking device 1100 extends between the proximal end of the covering
or braid layer 1180 and the extension region 1140, where the ePTFE or low friction
layer 1170 remains exposed. Preferably, this ePTFE or low friction region is the part
of the docking device 1100 that crosses the mitral plane and comes into contact with
the atrial side of the native leaflets. Meanwhile, the portion of the docking device
1100 that passes through the mitral valve can be, for example, the part of the exposed
central region 1110 just proximal to the end of the covering or braid layer 1180,
or can also include some of the proximal end of the covering or braid layer 1180 as
well.
[0090] Advancement of the lower coils or ventricular coils of the docking device 1100 into
the left ventricle should be precise. To facilitate this one or multiple marker bands
or other visualization features can be included on any of the docking devices described
herein. Fig. 21 shows a top view of a modified embodiment of the docking device 1100,
where two marker bands 1182, 1184 have been added to the docking device 1100. The
marker bands 1182, 1184 are positioned next to one another. While the marker band(s)
and/or visualization feature(s) can be placed at various locations, in Fig. 20, a
first marker band 1182 is positioned at the proximal end of the high friction layer
1180, while a second marker band 1184 is positioned a small distance away from the
proximal end of the high friction layer 1180. One marker band 1182 can be made thicker
than the other marker band 1184, in order to easily tell them apart. The marker bands
1182, 1184 or other visualization feature(s) provide landmarks to easily identify
the position of the proximal end of the high friction layer 1180 relative to both
the delivery catheter and the native mitral anatomy. Therefore, a physician can use
the marker bands 1182, 1184 or other visualization feature(s) to determine when to
stop advancing the docking device 1100 into the left ventricle (e.g., when the marker
bands are at a desired orientation proximate commissure A3P3), and to start releasing
or unsheathing the remaining proximal portion of the docking device 1100 into the
left atrium. In one embodiment, the marker bands 1182, 1184 are visualized under fluoroscopy
or other 2D imaging modality, but the invention should not be limited thereto. In
some embodiments, one or both marker bands are instead positioned on the low friction
layer 1170 proximal to the end of the braid layer 1180, or on other portions of the
docking device 1100, based on user preference. In other embodiments less or more marker
bands can be used. The braid layer 1180 can extend across the portion of the docking
device coils that engages the replacement heart valve.
[0091] Any of the docking devices herein can be further modified, for example, to ease or
assist in advancement of the docking device to an appropriate position relative to
the native valve. Modifications can also be made, for example, to help protect the
native valve and other native heart tissue from being damaged by the docking device
during implantation and positioning of the docking device. For mitral applications,
when a leading or distal tip of a coil-shaped docking device similarly as previously
described is introduced into and rotated into position in the left ventricle, the
distal tip can be sized, shaped, and/or otherwise configured to more easily navigate
around and encircle the chordae tendineae. On the other hand, the distal tip should
also be made in an atraumatic manner, such that advancement of the distal tip around
and/or through the mitral or other valve anatomy will not damage the anatomy.
[0092] Meanwhile, in some embodiments, the proximal end of the docking device is attached
to a pusher in the delivery catheter that pushes the docking device out of a distal
opening of the catheter. The terms pusher, pusher device, and push rod are used interchangeably
herein and can be substituted for each other. While attached to the docking device,
the pusher can assist in both pushing and pulling or retrieval of the docking device
relative to the delivery catheter, in order to enable repositioning of the docking
device at any stage throughout the delivery process. Methods described herein can
include various steps related to retrieval and repositioning of the docking device,
e.g., retracting or pulling a push rod/suture/tether or other feature to pull/retract
the docking device back into the delivery catheter, then repositioning and reimplanting
the docking device in a different position/orientation or location. For docking devices
that have a cover layer, such as a fabric layer, that covers a coil skeleton of the
docking device, adjustments of the docking device by the pusher can lead to friction
forces applied against the cover layer, particularly at portions located at the proximal
and distal ends of the docking device, for example, by the heart anatomy and/or by
the pusher/push rod/pusher device itself. Therefore, the structure at the ends of
the coil of the docking device and the connection techniques (e.g., adhesion or suturing
techniques) for connecting the fabric layer to the coil can both be important for
handling and dealing with such friction forces and to prevent tearing of the fabric
layer from the coil or the ends of the coil.
[0093] In view of the above considerations, the docking device 1100 can include atraumatic
distal and proximal tips. Fig. 22 shows a cross-section of the proximal tip of the
docking device 1100, showing the respective geometries of the wire core 1160, for
example, that can be made of NiTi, and a low friction cover layer 1170, for example,
that can be made of ePTFE or another polymer. The low friction cover layer 1170 can
extend slightly farther past the end of the wire core 1160 and taper down to a rounded
tip. The rounded extension region provides space for the low friction cover layer
1170 to anchor to and around the wire core 1160, while also forming an atraumatic
tip. The distal tip of the docking device devices herein (e.g., docking device 1100)
can be constructed or arranged to have a similar structure.
[0094] Referring to Figs. 19 and 22, the docking device 1100 can optionally further include
securing holes 1164 near each of the proximal tip and distal tip . The securing holes
1164 can be used to further secure the cover layer 1170 to the wire core 1160, for
example, via a suture or other tie-down. This and/or similar securing measures can
further prevent slipping or movement between the core 1160 and the cover layer 1170
during deployment and/or retrieval of the docking device 1100. Optionally, the cover
layer 1170 can be adhered, melted, molded, etc. around the core without suturing.
[0095] In some embodiments, the distal tip of the docking device 1100 can be tapered slightly
radially inwardly, for example, to be tangential to the circular shape formed by the
coils of the central region 1110. Similarly, the stabilization coil/turn or the upper
region 1130 of the docking device 1100 can also taper slightly radially inwardly,
for example, to be tangential (or have a portion that is tangential) to the circular
shape formed by the coils of the central region 1110, and can also be, for example,
pointed slightly upwards towards the atrial ceiling and away from the other coils
of the docking device 1100. The upper region 1130 of the docking device 1100 can be
configured in this manner as a precautionary measure, for example, in case the docking
device 1100 is not placed in the desired position discussed above and slides towards
the left ventricle, where the upper region 1130 could potentially come into contact
with the mitral plane, or if the docking device 1100 is being implanted into a heart
with an abnormal anatomy.
[0096] With respect to facilitating attachment of the docking device 1100 to a pusher/push
rod or other advancement or retrieval mechanism in the delivery catheter, the proximal
end of the docking device 1100 can further include a second hole or bore 1162. As
illustrated in Fig. 22A, the hole or bore 1162 can be sized such that a holding device,
such as a long release suture 1163, can be looped therethrough for connecting or attaching
the docking device 1100 to the distal end of the pusher or other feature of the delivery
catheter. The hole 1162 can be rounded and smooth to prevent unintended severing of
the release suture. The release suture provides a more secure attachment of the docking
device 1100 to the delivery catheter, and can also allow for a pulling retrieval of
the docking device 1100 when retraction of the position of the docking device 1100,
partial retrieval, or full retrieval is desired. Fig. 22C illustrates a closer view
of the release suture 163 looped through the bore 1162 of the docking device 1100,
where the exterior of the delivery catheter 1010 has been cut away. A pusher device
1165 is configured as a pusher tube with a lumen extending therethrough, e.g., from
end to end. The suture in this embodiment runs through a longitudinal bore through
the pusher device/tube 1165 held within the delivery catheter 1010. Meanwhile, once
a desired positioning of the docking device 1100 has been achieved, the physician
or other user can simply cut a proximal portion of the release suture and pull the
release suture proximally to pass the cut end of the suture out through the hole 1162,
thereby releasing the docking device 1100 from the delivery catheter. In one embodiment,
the suture can be looped and extended such that the suture extends from the bore 1162
through the pusher device/tube 1165 to a handle or hub external to the patient (the
loop can be closed or open with two ends secured to the handle or hub). When cut,
a portion of the suture can remain attached to the handle or hub (or be otherwise
held by the health care provider), which can allow the suture to be pulled proximally
until the cut end comes out of the bore 1162 to release the delivery device. Fig.
22B illustrates another embodiment of looping the suture 1163 to the proximal end
of the coil, through bore 1162.
[0097] Various further modifications can be made to either the distal tip or the proximal
tip of any of the docking devices described herein, or both tips, which can make the
docking device more robust. Fig. 23 shows a distal end of a coil skeleton or core
of a docking device according to another embodiment of the invention. The distal end
of the coil/core 710 can be made of or include Nitinol, another shape memory metal
or material, and/or non-shape memory materials. The distal end of the coil/core 710
has a substantially flat or rectangular cross-section, with a distal ring-shaped tip
712. The rectangular cross-section shown can either be shaped in such manner only
at a distal end of the coil 710, or can extend for the length of the coil 710, while
in other embodiments, the entire coil 710, including the distal end region, can have
a more round cross-section or otherwise shaped cross-section. The ring-shaped tip
712 has an enlarged or expanded width compared to other portions of the coil/core
710, and defines a through hole 714 to facilitate passing through of one or more sutures.
A free end 716 of the ring-shaped tip 712 can be arranged as a circular or otherwise
curved arc, while an opposite proximal end 718 of the tip 712 can be formed as a rounded
or tapered transition portion between the tip 712 and an adjacent region of the coil
710. Near the distal tip 712, the coil 710 can further include one or more cover anchoring
holes 720 to further assist in anchoring a cover layer that is placed over and attached
to the coil 710.
[0098] A cover layer that covers the coil skeleton/core 710 of the docking device can be,
for example, one or more of the coverings or layers (e.g., low friction and/or high
friction covering(s)) previously described. The cover layer can be made of or include,
for example, an ePTFE core tube that is wrapped with a woven PET cloth, or can be
made of or include any other fabric or other biocompatible material. Such a cover
layer can be used to cover a majority of the docking device, for example, from a main
body of the coil skeleton/core 710 up to or slightly over the end 718 of the distal
tip 712. The cover layer can then be connected to the ring-shaped distal tip 712,
for example, via sutures that are passed through the through hole 714 and that go
on top of and cover the arched free end region 716. The sutures serve to anchor the
cover layer to the coil skeleton/core 710, and also serve to soften the margins of
the ring-shaped distal tip 712. Additional sutures can also be passed through the
one or more cover anchoring holes 720 near the distal tip 712, to provide additional
anchoring of the cover layer to the coil skeleton/core 710.
[0099] Fig. 24 shows a distal end of a coil skeleton or core of a docking device that can
be used with any of the docking devices described herein. The distal end of the coil/core
810 can also be made of or include Nitinol, another shape memory metal or material,
and/or other non-shape memory materials. The distal end of the coil/core 810 has a
distal ball-shaped tip 812. The ball-shaped tip 812 can be preformed with the rest
of the coil skeleton/core 810, or can be a separate ball-shaped or a short cudgel-shaped
addition with a rounded end that is welded to or otherwise attached to the distal
end of the coil/core 810. Meanwhile, a small gap 814 is formed or left between the
ball-shaped tip 812 and the rest of the coil/core 810. The gap 814 can be approximately
0.6 mm or any other size that is sufficient to facilitate passing through and/or crossing
over of one or more sutures for anchoring or otherwise connecting a cover layer to
the distal end of the coil/core 810.
[0100] One or more cover layer(s) or covering(s) that covers the coil skeleton/core 810
of the docking device can be similar to previously described cover layers or coverings.
The cover layer(s)/covering(s) can be made of or include, for example, an ePTFE core
tube that is wrapped with a woven PET cloth, or can be made of or include any other
fabric or other biocompatible material. In one attachment method, such a cover layer/covering
covers a main body of the coil skeleton 810, over the gap 814, and up to or slightly
over the ball-shaped tip 812, while leaving a free end of the ball-shaped tip 812
exposed. The cover layer/covering is then connected to the distal end of the coil
810, for example, via sutures that are passed through the gap 814. In a second attachment
method, the entire ball-shaped tip 812 is wrapped with and fully covered by the cover
layer, and sutures are then passed through and/or crossed over the gap 814 to anchor
the entire cover layer over the end of the ball-shaped tip 812.
[0101] The distal tips 712, 812 as shown and described with respect to Figs. 23 and 24 provide
their respective docking devices with distal ends that are rounded with compact noses
that enable easier and more convenient navigation of their respective docking devices
within the left ventricle. In addition, since each of the tips 712, 812 is curved
or rounded, the tips 712, 812 form ends with soft edges. The shapes and structures
at the distal ends of the respective coil skeletons 710, 810, the type, texture, and
construction of the cover layer, and the suturing techniques for attaching the cover
layer to the coil skeletons 710, 810 also allow for tight connections between the
distal tips 712, 812 and the respective cover layers, without the use of glue or any
other adhesives. Furthermore, the tip construction and arrangements prevent exposure
of any sharp edges, and also prevent surfaces of the coil skeletons 710, 810 from
cutting and/or protruding out of the cover layers, as a result of any friction forces
that are applied to the cover layers of the docking devices during or after delivery.
[0102] As discussed above, in some embodiments, the docking device can be attachable to
a pusher that can more easily facilitate pushing and pulling of the docking device
for delivery and readjusting purposes. Fig. 25 shows a proximal end of a coil skeleton/core
910 of a docking device 900 (which can be the same as or similar to other docking
devices described herein), and Fig. 26 shows the proximal end of the docking device
900, with a cover layer 920 over the coil skeleton/core 910, and sutures 930 attaching
the cover layer 920 to the coil skeleton/core 910.
[0103] Referring first to Fig. 25, the coil skeleton/core 910 of the docking device 900
has a proximal end region that has a substantially flat or rectangular cross-section,
similar to the cross-section of the distal end of the coil/core 710 discussed above.
The rectangular cross-section shown can either be shaped in such manner only at the
proximal end region of the coil/core 910, or can extend for the length of the coil/core
910, while in other embodiments, the entire coil/core 910, including the proximal
end region, can have a more round cross-section or otherwise shaped cross-section.
An oval or elongate slit hole 912 extends through the proximal end region of the coil/core
910, where two flanks 914, 916 of the coil/core 910 extend along either side of the
slit hole 912 to connect the proximal free end 918 of the coil/core 910 to the rest
of the coil/core 910. The slit hole 912 has a width that is sufficient for passing
through or crossing of a needle and/or one or more sutures 930.
[0104] As shown in Fig. 26, the covering/cover layer 920 can be, for example, a covering,
fabric layer, or other layer the same as or similarly constructed as discussed above
with respect to previous embodiments of the docking device. The covering/cover layer
920 is wrapped around the coil skeleton/core 910, and is anchored to or otherwise
secured to the coil/core 910 by sutures 930 that run along and are passed through
the slit hole 912. The sutures 930 can be crossed through the slit hole 912 in an
"8" shape, as shown in Fig. 26, where a suture 930 is passed through the slit hole
912 at least twice and is wrapped around the opposite flanks 914, 916 of the coil/core
910 adjacent to the slit hole 912 at least one time each. In the embodiment shown,
the suture 930 is passed through the slit hole 912 at least four times, and is wrapped
around the flanks 914, 916 at either side of the slit hole 912 at least two times
each. The sutures 930 are positioned at or moved towards a proximal portion of the
slit hole 912, near the free end 918 of the coil skeleton/core 910, so that a distal
end of the slit hole 912 remains exposed and accessible to a user, and stays open
and large enough, for example, for a pull wire 940 (e.g., a release suture) of a pusher
of the delivery catheter to pass or cross through, thereby establishing a secure connection
between the docking device 900 and the pusher. The pull wire 940 can be a suture.
[0105] When the docking device 900 is connected to the pusher via the pull wire 940, either
a distal end of the pusher (not shown) abuts against the proximal free end of the
docking device 900 or the pull wire 940 abuts against the distal end of the slit hole
912, in order to advance the docking device 900 out of the delivery catheter. Meanwhile,
when it is desired for the docking device 900 to be pulled back or retracted, for
example, for readjusting a position of the docking device 900 at the implant site,
the pull wire 940 can be pulled proximally to retract the docking device 900 proximally
as well. Similar steps can be used with other docking devices herein. When the pull
wire 940 is pulled back, the pull wire abuts against the sutures 930 that extend through
the slit hole 912, which by virtue of the "8" shape suturing, forms a cross suture
region that serve to provide a cushioned landing region against which the pull wire
940 can abut. Therefore, the sutures 930 serve to anchor and attach the cover layer
920 to the coil skeleton/core 910, while also masking or covering the sharp edges
of the slit hole 912, to protect the pull wire 940 from being damaged or ruptured
by the docking device 900, and conversely to protect the docking device 900 from being
damaged by the pull wire 940, during retrieval or other pulling of the docking device
900.
[0106] Like the distal end arrangements discussed with respect to Figs. 23 and 24, the shape
and structure at the proximal end of the coil skeleton/core 910, the type, texture,
and construction of the covering/cover layer 920, and the connection technique (e.g.,
suturing technique) for attaching the covering/cover layer 920 to the coil skeleton/core
910, each contributes to a tight connection between the proximal end of the coil 910
and the covering/cover layer 920, and can be done without the use of glue or any other
adhesives (e.g., the suturing technique does not require these). Furthermore, the
tip construction and arrangement prevents exposure of any sharp edges, and also prevents
surfaces of the coil skeleton/core 910 from cutting and/or protruding out of the covering/cover
layer 920, as a result of any friction forces that are applied to the covering/cover
layer 920 of the docking device 900 during or after delivery.
[0107] In various other embodiments, any or all of the different features from the different
embodiments discussed above can be combined or modified, based on the needs of each
individual patient. For example, the different features associated with the various
different issues (e.g., flexibility, increasing friction, protection) can be incorporated
into docking devices as needed for each individual application, based on a particular
patient's specific characteristics or requirements.
[0108] Embodiments of docking devices herein have generally been discussed above with respect
to helping anchor replacement valves at the mitral position. However, as has also
been mentioned above, the docking devices, as described or slightly modified versions
thereof, can also be applied in similar manners to valve replacements at other valve
sites as well, for example, at the tricuspid, pulmonary, or aortic positions. Patients
that are diagnosed with insufficiencies at either position can exhibit enlarged annuli
that both prevent the native leaflets from properly coapting, and that also can cause
the annuli to become too large, too soft, or too otherwise diseased to securely hold
an expandable valve therein. Therefore, use of a rigid or semi-rigid docking device
can also be beneficial for anchoring a replacement valve at those valve sites as well,
for example, to prevent the replacement valves from dislodging during normal heart
function.
[0109] The docking devices herein can further be covered with one or more coverings or cover
layers, similarly as discussed above. In addition, cover layer(s) for any of these
applications can also be made of or include a material that promotes more rapid tissue
ingrowth. The cover layer can further be constructed to have a larger amount of surface
area, for example, with a velour film, porous surface, braided surface, etc., to further
bolster tissue ingrowth.
[0110] Docking devices similar to those discussed above, when applied to valves other than
the mitral valve, can also provide a more secure landing zone at those sites as well.
The docking devices and associated replacement valves can be applied similarly as
has been discussed with respect to implantation at the mitral valve. A possible access
point for tricuspid replacement can be, for example, transseptal access, while a possible
access point for aortic replacement can be, for example, transfemoral access, although
access to the respective valve sites is not limited thereto. The use of coil-shaped
docking devices as previously described at the other valve sites can also serve to
circumferentially cinch or clamp the native leaflets after deployment of the replacement
valve at the native annulus, for example, by virtue of the leaflets and other tissue
being sandwiched between coils of the docking device and being held in place by a
spring force of the docking device, which further prevents slipping or other movement
of the docking device and of the sandwiched tissue relative to the docking device,
and prevents unwanted growth or expansion of the native annulus over time.
[0111] For purposes of this description, certain aspects, advantages, and novel features
of the embodiments of this disclosure are described herein. The disclosed methods,
apparatus, and systems should not be construed as being limiting in any way. Instead,
the present disclosure is directed toward all novel and nonobvious features and aspects
of the various disclosed embodiments, alone and in various combinations and sub-combinations
with one another. The methods, apparatus, and systems are not limited to any specific
aspect or feature or combination thereof and can be combined, nor do the disclosed
embodiments require that any one or more specific advantages be present or problems
be solved.
[0112] Although the operations of some of the disclosed embodiments are described in a particular,
sequential order for convenient presentation, it should be understood that this manner
of description encompasses rearrangement, unless a particular ordering is required
by specific language set forth below. For example, operations or steps described sequentially
can in some cases be rearranged or performed concurrently. Moreover, for the sake
of simplicity, the attached figures may not show the various ways in which the disclosed
methods can be used in conjunction with other methods. Additionally, the description
sometimes uses terms like "provide" or "achieve" to describe the disclosed methods.
These terms are high-level abstractions of the actual operations that are performed.
The actual operations that correspond to these terms can vary depending on the particular
implementation and are readily discernible by one of ordinary skill in the art.
[0113] In view of the many possible embodiments to which the principles of the disclosure
can be applied, it should be recognized that the illustrated embodiments are only
preferred examples and should not be taken as limiting the scope of the disclosure.
Rather the scope of the disclosure is defined by the following claims.
[0114] The application further comprises the following embodiments:
In a first embodiment, a docking device for docking a prosthetic valve at a native
valve of a heart comprises a coiled anchor that comprises a proximal tip and a distal
tip; at least one central turn having a first thickness and defining a central turn
diameter; an extension having a length extending from an upper end of the at least
one central turn, the extension having a second thickness that is less than the first
thickness; an upper turn extending from an upper end of the transition portion, the
upper turn having a third thickness that is greater than the second thickness; wherein
the coiled anchor is configured to be implanted at the native valve with at least
a portion of the at least one central turn of the coiled anchor positioned in a chamber
of the heart and around valve leaflets of the native valve.
[0115] In a second embodiment of the device according to the first embodiment, the first
thickness is at least 0.8 mm and the second thickness is between 0.4 to 0.8 mm.
[0116] In a third embodiment of the device according to any one of the first and the second
embodiments, the coil has a rectangular cross-sectional shape, and the first thickness
and second thickness are widths.
[0117] In a fourth embodiment of the device according to any one of the first and the second
embodiments, the coil has a circular or elliptical cross-sectional shape, and the
first thickness and second thickness are diameters.
[0118] In a fifth embodiment of the device according to any one of the first to the fourth
embodiments, the extension length is between 5 to 100 mm, and creates a vertical separation
between the at least one central turn and the upper turn.
[0119] In a sixth embodiment of the device according to any one of the first to the fifth
embodiments, the at least one central turn diameter is between 20 to 30 mm.
[0120] In a seventh embodiment of the device according to any one of the first to the sixth
embodiments, the first thickness and the second thickness are the same.
[0121] In an eighth embodiment, the device according to any one of the first to the seventh
embodiments further comprises a lower turn extending from the at least one full or
partial central turn, the lower turn having the first thickness and defining a lower
turn diameter that is greater than the central turn diameter.
[0122] In a ninth embodiment of the device according to the eighth embodiment, the third
thickness is the same as the first thickness and the upper turn comprises a first
diameter along a first axis and a second diameter along a second axis, wherein the
first axis diameter is greater than the central turn diameter, and wherein the second
axis diameter is greater than the central turn diameter and less than the lower turn
diameter.
[0123] In a tenth embodiment of the device according to any one of the eighth and the ninth
embodiments, the lower turn diameter is between 30 to 75 mm.
[0124] In an eleventh embodiment of the device according to the ninth embodiment, the first
axis diameter is between 40 to 75 mm and the second axis diameter is larger than the
diameter defined by the central turn.
[0125] In a twelfth embodiment of the device according to any one of the ninth and the eleventh
embodiments, the first axis diameter is between 40 to 80 mm, and the second axis diameter
is between 20 to 80 mm.
[0126] In a thirteenth embodiment of the device according to any one of the first to the
twelvth embodiments, at least one central turn comprises between one-half to 5 turns,
and the upper turn comprises between one-half to one turn.
[0127] In a fourteenth embodiment of the device according to any one of the eighth to the
tenth embodiments, the lower turn comprises between 1 and 5 turns.
[0128] In a fifteenth embodiment, the device according to any one of the first to the fourteenth
embodiments further comprises a cover layer comprised of a biocompatible material,
wherein the cover layer surrounds the coiled anchor.
[0129] In a sixteenth embodiment of the device according to the fifteenth embodiment, the
cover layer comprises pores having a diameter of 30 to 100 microns.
[0130] In a seventeenth embodiment of the device according to any one of the fifteenth and
the sixteenth embodiments, the cover layer extends at least along the portion of the
coiled anchor that is configured to be in contact with a replacement valve.
[0131] In an eighteenth embodiment of the device according to any one of the fifteenth to
the seventeenth embodiments, the coiled anchor further comprises securing holes near
each of the proximal and distal tips.
[0132] In a nineteenth embodiment of the device according to the eighteenth embodiment,
the cover layer is secured to the coiled anchor with sutures extending through the
securing holes of the coiled anchor and through the cover layer.
[0133] In a twentieth embodiment, the device according to any one of the fifteenth to the
nineteenth embodiments further comprises a friction enhancing element that comprises
a second cover layer surrounding and extending along at least a length of portion
of the length of the cover layer, wherein the second cover layer is connected to the
first cover layer by sutures and provides a coefficient of friction of at least 1.
[0134] In a twenty-first embodiment of the device according to the twentieth embodiment,
the second cover layer is a braided material.
[0135] In a twenty-second embodiment of the device according to any one of the twentieth
and the twenty-first embodiments, the second cover layer is a woven material.
[0136] In a twenty-third embodiment of the device according to any one of the twentieth
to the twenty-second embodiments, the second cover layer comprises pores having a
diameter ranging in size from 30 to 100 microns.
[0137] In a twenty-fourth embodiment, the device according to any one of the seventeenth
to the nineteenth embodiments further comprises at least one friction enhancing element
that comprises a plurality of bulges on the surface of the coiled anchor or on the
surface of the cover layer.
[0138] In a twenty-fifth embodiment, the device according to any one of the first to the
nineteenth embodiments further comprises at least one friction enhancing element that
comprises a plurality of lock and key cutouts in the outer surface of the coiled anchor.
[0139] In a twenty-sixth embodiment of the device according to the twenty-fifth embodiment,
the lock cutouts are grooves formed in the outer surface of the coiled anchor, and
the keys are protrusions extending outward from the coiled anchor, sized and shaped
to fit into the lock cutouts.
[0140] In a twenty-seventh embodiment, the device according to any one of the first to the
nineteenth embodiments further comprises a suture removeably threaded through a bore
at the proximal tip and configured to be connected to a pusher device within a delivery
catheter for retrieving the docking device.
[0141] In a twenty-eighth embodiment of the device according to the twenty-seventh embodiment,
the suture is removeably threaded through the bore at a location along a length of
the suture and then the suture ends are threaded through a space between the central
point of the suture and the proximal tip of the coiled anchor.
[0142] In a twenty-ninth embodiment, the device according to any one of the first to the
twenty-eighth embodiments further comprises a low friction cover layer, the low friction
cover layer having a distal end and a proximal end, surrounding the coiled anchor
and extending along a length of the coiled anchor, past the distal tip, and past the
proximal tip, the low friction cover layer having a rounded or tapered tip at its
distal end and at its proximal end.
[0143] In a thirtieth embodiment of the device according to any one of the first to the
twenty-eighth embodiments, the distal tip of the coiled anchor is tapered slightly
radially inward in a direction tangential to a circular shape formed by the central
turn.
[0144] In a thirty-first embodiment of the device according to any one of the first to the
twenty-eighth embodiments, the proximal tip of the coiled anchor is tapered slightly
radially inwardly and is pointed in an upward direction.
[0145] In a thirty-second embodiment, a system for implanting a docking device according
to any one of the first to the thirty-first embodiments at the native valve comprises
a delivery catheter; a suture threaded through a bore in a proximal end of the delivery
device; and a pusher device disposable in the delivery catheter; wherein the pusher
device includes a central lumen; wherein the suture is disposable in the central lumen
such that pulling the suture and/or the pusher device proximally relative to the delivery
catheter retracts the coiled anchor into the delivery catheter.
[0146] In a thirty-third embodiment of the system according to the thirty-second embodiment,
the suture is threaded through the bore at a location along a length of the suture
and then the suture ends are threaded through a space between the central point of
the suture and the proximal end of the coiled anchor.
[0147] In a thirty-fourth embodiment, a docking device for docking a prosthetic valve at
a native valve of a heart comprises a coiled anchor that comprises at least one central
turn defining a central turn diameter; a lower turn extending from the at least one
central turn defining a diameter that is greater than the central turn diameter; an
upper turn connected to the at least one central turn, the upper turn being shaped
to have a first diameter along a first axis and a second diameter along a second axis,
wherein the first axis diameter is greater than the central turn diameter, and wherein
the second axis diameter is greater than the central turn diameter and less than the
lower turn diameter; and wherein the coiled anchor is configured to be implanted at
the native valve with at least a portion of the at least one central turn of the coiled
anchor positioned in a chamber of the heart and around valve leaflets of the native
valve.
[0148] In a thirty-fifth embodiment of the device according to the thirty-fourth embodiment,
the at least one central turn defines a diameter between 20 to 30 mm.
[0149] In a thirty-sixth embodiment of the device according to any one of the thirty-fourth
and the thirty-fifth embodiments, the lower turn defines a diameter between 30 to
75 mm.
[0150] In a thirty-seventh embodiment of the device according to any one of the thirty-fourth
to the thirty-sixth embodiments, the first axis diameter is between 40 to 80 mm, and
the second axis diameter is between 20 to 80 mm.
[0151] In a thirty-eighth embodiment of the device according to any one of the thirty-fourth
to the thirty-sixth embodiments, the first axis diameter is 40 to 75 mm, and the second
axis diameter is larger than the diameter defined by the at least one central turn.
[0152] In a thirty-ninth embodiment of the device according to any one of the thirty-fourth
to the thirty-eighth embodiments, the coiled anchor comprises a coiled wire having
a rectangular cross-sectional shape with a thickness of at least 0.8 mm.
[0153] In a fortieth embodiment of the device according to any one of the thirty-fourth
to the thirty-eighth embodiments, the coiled anchor comprises a coil that has a circular
or elliptical cross-sectional shape with a thickness of at least 0.8 mm.
[0154] In a forty-first embodiment of the device according to any one of the thirty-fourth
to the fortieth embodiments, the at least one central turn comprises between one half
rotation turn to five full-rotation turns, the upper turn comprises between one half
turn to one turn, and the lower turn comprises between one half turn to five turns.
[0155] In a forty-second embodiment, the device according to any one of the thirty-fourth
to the forty-first embodiments further comprises a suture removeably threaded through
a bore in the coiled anchor and configured to be connected to a pusher device within
a delivery catheter to provide a means for retrieving the docking device.
[0156] In a forty-third embodiment of the device according to the forty-second embodiment,
the suture is removeably threaded through the bore at a location along a length of
the suture and then the suture ends are threaded through a space between the central
point of the suture and the proximal end of the coiled anchor.
[0157] In a forty-fourth embodiment, the device according to any one of the thirty-fourth
to the forty-third embodiments further comprises a low friction cover layer, having
a distal end and a proximal end, surrounding the coiled anchor and extending along
a length of the coiled anchor, past a distal tip of the coiled anchor, and past a
proximal tip of the coiled anchor, the low friction cover layer tapering to a rounded
tip at its distal end and at its proximal end.
[0158] In a forty-fifth embodiment of the device according to the forty-fourth embodiment,
the distal tip of the coiled anchor is tapered slightly radially inward in a direction
tangential to a circular shape formed by the central turn.
[0159] In a forty-sixth embodiment of the device according to the forty-fourth embodiment,
the proximal tip of the coiled anchor is tapered slightly radially inwardly and is
pointed in an upward direction.
[0160] In a forty-seventh embodiment of the device according to any one of the thirty-fourth
to the forty-sixth embodiments, the coiled anchor further comprises an extension having
a length extending from an upper end of the central turn comprising a second thickness
that is less than a first thickness of the upper turn.
[0161] In a forty-eighth embodiment of the device according to any one of the thirty-fourth
to the forty-seventh embodiments, at least a portion of the extension extends vertically
at an angle of between 70-110 degrees relative to the at least one central turn.
[0162] In a forty-ninth embodiment, a system for implanting a docking device according to
any one of the thirty-fourth to the forty-eighth embodiments at the native valve comprises
a delivery catheter; a suture threaded through a bore in a proximal end of the delivery
device; and a pusher device, wherein the pusher device includes a central lumen; wherein
the pusher device is disposable in the delivery catheter and the suture is disposable
in the central lumen such that pulling the suture and/or the pusher device proximally
relative to the delivery catheter retracts the coiled anchor into the delivery catheter.
[0163] In a fiftieth embodiment, a docking device for docking a prosthetic valve at a native
valve of a heart comprises a coiled anchor that comprises a proximal tip and a distal
tip; at least one full or partial central turn defining a diameter; an upper turn
connected to the at least one full or partial central turn; a cover layer surrounding
the coiled anchor along at least a part of the at least one full or partial central
turn, and wherein the cover layer is connected to the coiled anchor; at least one
friction enhancing layer disposed over the cover layer, wherein the at least one friction
enhancing layer is disposed over at least a portion of the at least one full or partial
central turn and no portion of the upper turn is covered by the friction enhancing
layer; and wherein the coiled anchor is configured to be implantable at the native
valve with at least a portion of the at least one full or partial central turn of
the coiled anchor positioned in a chamber of the heart and around valve leaflets of
the native valve.
[0164] In a fifty-first embodiment of the device according to the fiftieth embodiment, the
cover layer comprises pores having a diameter of 30 to 100 microns.
[0165] In a fifty-second embodiment of the device according to any one of the fiftieth and
the fifty-first embodiments, the cover layer extends at least along a portion of the
coiled anchor that is configured to be in contact with a replacement valve.
[0166] In a fifty-third embodiment of the device according to any one of the fiftieth to
the fifty-second embodiments, the coiled anchor further comprises securing holes near
each of the proximal and distal tips.
[0167] In a fifty-fourth embodiment of the device according to the fifty-third embodiment,
the cover layer is secured to the coiled anchor with sutures extending through the
securing holes of the coiled anchor and through the cover layer.
[0168] In a fifty-fifth embodiment of the device according to any one of the fiftieth to
the fifty-fourth embodiments, the friction enhancing layer is connected to the first
cover layer by sutures and provides a coefficient of friction of at least 1.
[0169] In a fifty-sixth embodiment of the device according to any one of the fiftieth to
the fifty-fifth embodiments, the friction enhancing layer is a braided material.
[0170] In a fifty-seventh embodiment of the device according to any one of the fiftieth
to the fifty-sixth embodiments, the friction enhancing layer is a woven material.
[0171] In a fifty-eighth embodiment, the device according to any one of the fiftieth to
the fifty-seventh embodiments further comprises a lower turn extending from a lower
end of the at least one full or partial central turn.
[0172] In a fifty-ninth embodiment, the device according to any one of the fiftieth to the
fifty-eighth embodiments further comprises at least two radiopaque markers positioned
along the at least one full or partial central turn.
[0173] In a sixtieth embodiment of the device according to any one of the fiftieth to the
fifty-seventh and the fifty-ninth embodiments, the at least one full or partial central
turn defines a diameter between 20 to 30 mm, wherein a lower turn extending from the
central turn defines a diameter between 30 to 75 mm, and wherein the upper turn has
a first axis diameter between 40 to 80 mm and a second axis diameter between 20 to
80 mm.
[0174] In a sixty-first embodiment, the device according to any one of the fiftieth to the
sixtieth embodiments further comprises a suture removeably threaded through a bore
at the proximal tip and configured to be connected to a pusher device within a delivery
catheter to provide a means for retrieving the docking device.
[0175] In a sixty-second embodiment of the device according to the sixty-first embodiment,
the suture is removeably threaded through the bore at a location along a length of
the suture and then the suture ends are threaded through a space between the central
point of the suture and the proximal end of the coiled anchor.
[0176] In a sixty-third embodiment of the device according to any one of the fiftieth to
the sixty-second embodiments, the cover layer is a low friction cover layer, having
a distal end and a proximal end, surrounding the coiled anchor and extending along
a length of the coiled anchor, past the distal tip, and past the proximal tip, the
low friction cover layer tapering to a rounded tip at its distal end and at its proximal
end.
[0177] In a sixty-fourth embodiment of the device according to any one of the fiftieth to
the sixty-third embodiments, the distal tip of the coiled anchor is tapered slightly
radially inward in a direction tangential to a circular shape formed by the central
turn.
[0178] In a sixty-fifth embodiment of the device according to any one of the fiftieth to
the sixty-fourth embodiments, the coiled anchor further comprises an extension having
a length extending from an upper end of the central turn comprising a second thickness
that is less than the thickness of the upper turn.
[0179] In a sixty-sixth embodiment, a docking device for docking a prosthetic valve at a
native valve of a heart comprises a coiled anchor that comprises a proximal tip and
a distal tip; at least one full or partial central turn defining a diameter; an upper
turn connected to the at least one full or partial central turn; a cover layer surrounding
the coiled anchor along at least a part of the at least one full or partial central
turn, wherein the cover layer is connected to the coiled anchor; at least one friction
enhancing element that comprises a plurality of bulges on the surface of the coiled
anchor or on the surface of the covering; and wherein the coiled anchor is configured
to be implantable at a native valve with at least a portion of the at least one full
or partial central turn of the coiled anchor positioned in a chamber of the heart
and around valve leaflets of the native valve.
[0180] In a sixty-seventh embodiment of the device according to the sixty-sixth embodiment,
the cover layer extends at least along the portion of the coiled anchor that is configured
to be in contact with a replacement valve.
[0181] In a sixty-eighth embodiment of the device according to any one of the sixty-sixth
to the sixty-seventh embodiments, the coiled anchor further comprises securing holes
near each of the proximal and distal tips, and the cover layer is secured to the coiled
anchor with sutures extending through the securing holes of the coiled anchor and
through the cover layer.
[0182] In a sixty-ninth embodiment of the device according to any one of the sixty-sixth
to the sixty-eighth embodiments, the friction enhancing element is a braided material.
[0183] In a seventieth embodiment of the device according to any one of the sixty-sixth
to the sixty-ninth embodiments, the friction enhancing element is a woven material.
[0184] In a seventy-first embodiment, the device according to any one of the sixty-sixth
to the seventieth embodiments further comprises at least two radiopaque markers positioned
along the at least one full or partial central turn.
[0185] In a seventy-second embodiment of the device according to any one of the sixty-sixth
to the seventy-first embodiments, the at least one full or partial central turn defines
a diameter between 20 to 30 mm, wherein a lower turn extending from the central turn
defines a diameter between 30 to 75 mm, and wherein the upper turn has a first axis
diameter between 40 to 80 mm and a second axis diameter between 20 to 80 mm.
[0186] In a seventy-third embodiment, the device according to any one of the sixty-sixth
to the seventy-second embodiments further comprises a suture removeably threaded through
a bore at the proximal tip and configured to be connected to a pusher device within
a delivery catheter to provide a means for retrieving the docking device.
[0187] In a seventy-fourth embodiment of the device according to the seventy-third embodiment,
the suture is removeably threaded through the bore at a location along a length of
the suture and then the suture ends are threaded through a space between the central
point of the suture and the proximal end of the coiled anchor.
[0188] In a seventy-fifth embodiment of the device according to any one of the sixty-sixth
to the seventy-fourth embodiments, the coiled anchor further comprises an extension
having a length extending from an upper end of the central turn comprising a second
thickness that is less than the thickness of the upper turn.
[0189] In a seventy-sixth embodiment, a docking device for docking a valve prosthesis at
a native valve of a heart comprises a coiled anchor that comprises a proximal tip
and a distal tip; at least one full or partial central turn defining a diameter; an
upper turn connected to the at least one full or partial central turn; at least one
friction enhancing element that comprises a plurality of lock and key cutouts in the
outer surface of the coiled anchor; wherein the coiled anchor is configured to be
implantable at the native valve with at least a portion of the at least one full or
partial central turn of the coiled anchor positioned in a chamber of the heart and
around valve leaflets of the native valve.
[0190] In a seventy-seventh embodiment of the device according to the seventy-sixth embodiment,
the lock cutouts are grooves formed in the outer surface of the coiled anchor, and
the keys are protrusions extending outward from the coiled anchor, sized and shaped
to fit into the lock cutouts.
[0191] In a seventy-eighth embodiment of the device according to any one of the the seventy-sixth
and the seventy-seventh embodiments, the at least one full or partial central turn
defines a diameter between 20 to 30 mm, wherein a lower turn extending from the central
turn that defines a diameter between 30 to 75 mm, and wherein the upper turn has a
first axis diameter between 40 to 80 mm and a second axis diameter between 20 to 80
mm.
[0192] In a seventy-ninth embodiment, the device according to any one of the the seventy-sixth
to the seventy-eighth embodiments further comprises a suture removeably threaded through
a bore at the proximal tip and configured to be connected to a pusher device within
a delivery catheter to provide a means for retrieving the docking device, wherein
the suture is removeably threaded through the bore at a location along a length of
the suture and then the suture ends are threaded through a space between the central
point of the suture and the proximal end of the coiled anchor.
[0193] In an eightieth embodiment of the device according to any one of the the seventy-sixth
to the seventy-ninth embodiments, the distal tip of the coiled anchor is tapered slightly
radially inward in a direction tangential to a circular shape formed by the central
turn, and the proximal tip of the coiled anchor is tapered slightly radially inwardly
and is pointed in an upward direction.
[0194] In an eighty-first embodiment of the device according to any one of the the seventy-sixth
to the eightieth embodiments, the coiled anchor further comprises an extension having
a length extending from an upper end of the central turn comprising a second thickness
that is less than the thickness of the upper turn.
[0195] In an eighty-second embodiment, the device according to any one of the the seventy-sixth
to the eighty-first embodiments further comprises at least two radiopaque markers
positioned along the at least one full or partial central turn.
[0196] In an eighty-third embodiment, a system for implanting a docking device at a native
valve of a heart comprises a delivery catheter; a docking device having a coiled anchor
with a proximal tip, a distal tip, and a proximal end, wherein the proximal end includes
a bore; a suture threaded through the bore; and a pusher device, wherein the pusher
device includes a central lumen; wherein the pusher device can be disposed in the
delivery catheter and the suture can be disposed in the central lumen such that pulling
the suture can pull the coiled anchor against the pusher device and retracting the
pusher device and suture proximally relative to the delivery catheter can retract
the coiled anchor into the delivery catheter.
[0197] In an eighty-fourth embodiment of the system according to the eighty-third embodiment,
the suture is threaded through the bore at a location along a length of the suture
and then the suture ends are threaded through a space between the central point of
the suture and the proximal end of the coiled anchor.
[0198] In an eighty-fifth embodiment, the system according to any one of the eighty-third
and the eighty-fourth embodiments further comprises a low friction cover layer, having
a distal end and a proximal end, surrounding the coiled anchor and extending along
a length of the coiled anchor.
[0199] In an eighty-sixth embodiment of the system according to any one of the eighty-third
to the eighty-fifth embodiments, the distal tip of the coiled anchor is tapered slightly
radially inward in a direction tangential to a circular shape formed by the central
turn, and the proximal tip of the coiled anchor is tapered slightly radially inwardly
and is pointed in an upward direction.
[0200] In an eighty-seventh embodiment of the system according to any one of the eighty-third
to the eighty-sixth embodiments, the docking device further comprises an upper turn
defining a first diameter, and a central turn connected to the upper turn, the central
turn defining a diameter that is less than the first diameter.
[0201] In an eighty-eighth embodiment of the system according to the eighty-seventh embodiment,
the docking device further comprises a lower turn connected to the central turn, the
lower turn defining a diameter that is greater than a diameter defined by the central
turn.
[0202] In an eighty-ninth embodiment, the system according to any one of the eighty-third
to the eighty-eighth embodiments further comprises a guide sheath that defines a guide
sheath lumen in which the delivery catheter can be disposed.
[0203] In a ninetieth embodiment, a docking device for docking a prosthetic valve at a native
valve of a heart comprises a coiled anchor that comprises a proximal tip and a distal
tip; a hollow tube having a proximal end and a distal end; a plurality of cuts through
portions of the tube; a wire having a length, a proximal end, and a distal end; wherein
the distal end of the wire is secured to a distal end of the hollow tube and the proximal
end of the wire is secured to a proximal end of the hollow tube; wherein the length
of the wire extends through the hollow tube and applies a radially inward tension
on the hollow tube; wherein the hollow tube is configured to at least partially encircle
leaflets of a native valve or other native tissue and provide a docking surface for
an expandable valve.
[0204] In a ninety-first embodiment of the device according to the ninetieth embodiment,
the cuts have a pattern and shape that incorporates both longitudinal and transverse
cuts forming teeth and grooves in the hollow tube.
[0205] In a ninety-second embodiment of the device according to any one of the ninetieth
and the ninety-first embodiments, the proximal end and distal end are crimped.
[0206] In a ninety-third embodiment of the device according to any one of the ninetieth
to the ninety-second embodiments, a plurality of cuts in a lower turn of the coiled
anchor are greater in size than cuts in central and upper turns of the coiled anchor.
[0207] In a ninety-fourth embodiment of the device according to any one of the ninetieth
to the ninety-second embodiments, the distal end comprises at least one distal cut
at the distal end and the proximal end comprises at least one proximal cut at the
proximal end, wherein the distal cut and the proximal cut are sized and/or shaped
differently from the plurality of cuts.
[0208] In a ninety-fifth embodiment, the device according to any one of the ninetieth to
the ninety-fourth embodiments further comprises a central turn defining a diameter
between 20 to 30 mm.
[0209] In a ninety-sixth embodiment, the device according to the ninety-fifth embodiment
further comprises a lower turn extending from a lower end of the central turn defining
a diameter greater than the central turn diameter, wherein the lower turn diameter
is between 30 to 75 mm.
[0210] In a ninety-seventh embodiment, the device according to any one of the ninety-fifth
and the ninety-sixth embodiments further comprises an upper turn extending from an
upper end of the central turn, having a first diameter along a first axis and a second
diameter along a second axis, wherein the first axis diameter is greater than the
central turn diameter and wherein the second axis diameter is greater than the central
turn diameter and less than the lower turn diameter.
[0211] In a ninety-eighth embodiment of the device according to any one of the ninetieth
to the ninety-seventh embodiments, the coiled anchor has a rectangular cross-sectional
shape, and a thickness of at least 0.8 mm.
[0212] In a ninety-ninth embodiment of the device according to any one of the ninetieth
to the ninety-seventh embodiments, the coil has a circular or elliptical cross-sectional
shape, with a thickness of at least 0.8 mm.
[0213] In a hundredth embodiment, the device according to any one of the ninetieth to the
ninety-ninth embodiments further comprises a suture removeably threaded through the
bore and configured to be connected to a pusher device within a delivery catheter
to provide a means for retrieving the docking device.
[0214] In a hundred-and-first embodiment, the device according to any one of the ninetieth
to the hundredth embodiments further comprises a low friction cover layer, having
a distal end and a proximal end, surrounding the coiled anchor and extending along
a length of the coiled anchor, past the distal tip, and past the proximal tip, the
low friction cover layer tapering to a rounded tip at its distal end and at its proximal
end.
[0215] In a hundred-and-second embodiment, a method of implanting a docking device for a
prosthetic valve at a native heart valve comprises the steps of positioning a distal
end of a delivery catheter into a first chamber of a heart, wherein the delivery catheter
contains a docking device in a first configuration inside the delivery catheter, and
wherein the docking device is configured to transition to a second configuration having
at least one central turn defining a central diameter, an extension having a length
extending from an upper end of the at least one central turn, and an upper turn extending
from an upper end of the extension when unconstrained by the delivery catheter; advancing
a distal end of the docking device from the delivery catheter, through a commissure
of the native heart valve, and into a second chamber of the heart such that the docking
device encircles chordae and/or native leaflets of the native valve, and wherein the
docking device is advanced such that the upper end of the extension of the docking
device is positioned in the first chamber; releasing the upper turn of the docking
device in the first chamber, such that the upper turn contacts a wall of the first
chamber; inserting a replacement valve in an inner space defined by the docking device;
and radially expanding the replacement valve until there is a retention force between
the replacement valve and the docking device to hold the replacement valve in a stable
position.